A very brief word about this SEO resource! 

All of the tips you'll read below are all the ingredients in a big pot of SEO soup. When mixed together, they help determine your page rank, your SERP (Search Engine Results Page) standings, and any other ranking method that may arise in the near future. Aside from a dramatically large number of backlinks, no single portion of the soup will drastically improve your rankings!

Domain Names (URLs) and SEO 

• Having the actual keyword(s) in your domain name will help highlight your site in a search result. Search engines like Google will bold words within URLs, if they were a part of someone's search query. For example, go to Google and search for "apple," and note how the link for "www.apple.com" has the word "apple" displayed in bold. It simply helps one's eye catch a URL name while skimming a results page. Although this may not sound like much, it may help pull in a couple curious clicks.
• Search engines don't discriminate against dashes within URLs in most cases. For instance, "my-site" and "my site" are identical in the eyes of a search engine. The less favorable underscore, "my_site" is also a part of that group. Both the dash and the underscore are converted to a space as a search engine spider reads them. (therefore, "my-site" is not equal to "mysite", but it is equal to "my site").
• Having a site name that is extremely relevant to what your site is about is a definite strength. For instance, if your site is about "tables" and your website name is "buytables.com," you have a major advantage.
• When it comes to the rest of your URL, make sure its search engine friendly. For instance, a URL like "Mysite.com/11/bin/ap1d7kfx/1.php" will have a difficult time being read by search engines, whereas "Mysite.com/products/tables/antique-oak-tables.php" will have the obvious advantage. This is an incredibly big problem for sites that utilize dynamic URLS (URLs that are generated by a web site, that are called forth from a database).
• Domain hacks are a fun way to create a variety of new URLs. The most famous domain hack is "del.icio.us." It involves registering a partial domain name (in that case, icio.us) and appending a subdomain (del) to the URL. While these can be fun and rather brandable, there is practically no SEO benefit in doing so.

Content and SEO 

• All content must be personally written from scratch. Search engines know when something has been copied and pasted from another site...even if that site is ranked millions of pages back in a search query! Your site will be penalized if it is using copied & pasted editorial.
• Proper spelling and grammar counts to search engines!
• Content that is regularly updated will be noticed by search engines. It helps them know that you're paying attention to your content, and updating obsolete information.
• Emphasize important terms and keywords within your content using bold and italics. They'll stand out to search engine spiders, and help rank your page. That goes for the occasional word or phrase fragment...NOT an entire paragraph!
• Remember that PDF documents are also spidered by search engines. Upload your company's sales information in a downloadable PDF format - much of the content within them may bring in unique hits.
• Keyword saturation is a HUGE part of SEO. It involves the number of times your most important keywords are repeated on a single page. Most webmasters aim to get 3%-7% saturations for their most valued keywords or keyword strings. It's generally dangerous to get above 10% saturation for a word, as that may involve search engine penalties. Look at your keyword saturation by using a keyword density checker, or this tool for 2+ word keyword density.

Source Code Meta and SEO 

• Title: This tag sets your "website name" at the top left corner of a browser. It does much more, though - it is used as another small determining factor for a browser to get a glimpse of what your site is about. Tweak your title tag to include only a few major keywords about your site, followed by your site name. It is not unusual to get a high search engine ranking just for a particular keyword that you've inserted in your title tag, as long as it is further backed up in your page content.
• Meta Tags: As you may already know, these are the keywords that are manually set to a webpage. They are still used by search engines to help determine the "gist" of what your page is about. A common misconception is to think that Meta Tags should be single words; when in fact, they can actually be phrases as well. For instance, if your TV fan site has meta keywords "tv, television, sitcoms, programs" - try adding "wednesday afternoon primetime shows, nightly news programs, shows for children". Of course, these are just examples. Do some research to find out the best combinations for your site! Another great tip: use misspellings to increase your chances of being listed, for when people misspell a word in a Google search! This will not negatively impact your rankings.
• ALT Tags: ALT tags are very commonly ignored. Originally, they added a text description in the place of a non-loading image, which was intended for browers that were text-only. Today, they help search engines determine what the picture is about, which is then co-related to the information around it. In turn, it is added to the overall "view" of the page, and may help rank your site better. Improve it by adding relevant keywords about that image, or keywords important to the page that a particular image is located on.
• TITLE Tags: (Not to be confused with Page Title) TITLE tags define what your hyperlink is about. Think of it as the "ALT" tag of hyperlinks! By setting a TITLE tag for your hyperlinks, you are further emphasizing what they are about, therefore improving your site's optimization as spiders reference this information and put more weight on your links for it.
• Headings: Also known as the H-tags (H1, H2, H3, etc); headings help a search engine see the "hierarchy" of content on your site. For instance, use H1 on the main title of a page (don't confuse this with the "title tag," we're talking about body content right now). Use H2 on the sub-title that falls under the main title. Continue this hierarchy for the rest of your page. Search engines will notice the main and sub titles, helping them realize how content flows. If you don't like the way headings look, you can always change their size in the CSS stylesheet. For instance, you can set H1, H2 and H3 to 12pt Arial if you wanted, without losing the benefit of any of those H-tags.
• Hyperlinks: There's so much more you can do with a hyperlink. Rather than stating: "For the best sports car resource, click here," try: "The best sports car resource." By including keywords within the URL itself, you're helping to boost the hyperlink's importance in regard to those words.
• Anchors: Anchors are links that "zoom" down to another specified area on the same page as that link. In terms of SEO, they help emphasize what certain areas of a page are about. It's good practice to use anchors to point to each section on a long page.

Site Design and SEO 

• Never, ever include content (text) within Ajax, Flash, JPG images, or any other format that search engines can't read. If the spider can't see it, you won't get credit for it in search engine rankings.
• Don't nest content within too many tables. In other words, if you have content that is within a table that is within another table that is within another table (and so on), the search engine will find it to be unfavorable.
• If your website software utilizes tags, use them to their fullest capacity. Tags are used by search engines to link relevant pages within the same website together. So, link all "car" pages with tags like "cars, automobiles", etc. Sometimes, your site will appear in a search result purely because of a tag that is assigned to a page!
• In all, make sure your site is as easy as possible for a search engine to spider it.

Backlinks and SEO 

• Websites that link to your site will improve your rankings. Contact other webmasters, and offer to link to their sites in exchange for them linking to yours...or see if they have an advertising plan for such a thing. What's even more important is if their site also pertains to the same topic or theme of your website!
• Thanks to the no-follow attribute script, some links pointing to your site might not count at all as a backlink. Websites including Wikipedia (and many other wikis), message boards, and most large or famous websites that allow community added content are included in the fray. Without it, everyone would be promoting their website for free, and spamming would be out of control! In short, if a big-name site allows you to add a link to their page, then 9 chances out of 10, it is using the no-follow attribute. Now you know why the backlink purchasing market is making more money than ever...
• Backlinks that come from your other websites probably will not count. Search engines put very little (if any at all) emphasis on backlinks coming from sites that are located on the same server or IP address.
• Clicks that come from e-mail referrals are indeed being noticed, and count as great links - even though they are not "static" or permanently live on the internet.

Cheating and SEO 

• If a technique seems too good to be true, it probably is. Everything listed on this page is 100% legit for safe SEO practices.
• Many illegal resources and e-books exist, that teach black hat or "illegal" search engine optimization practices. You'd only be fooling yourself by attempting them. Remember, your site could be banned permanently from Google and others.

Site Submission and SEO 

• Services that advertise "We'll submit your site to 1,000 search engines" might be more hurtful than helpful. It's best to submit your site only the major search engines, and let the rest "collect" your site afterwards. To be safe, submit to 1) Google, 2) Yahoo, 3) DMOZ.org. These three sites "syndicate" your site to the others. Note that getting added to DMOZ.org now takes years - but the other two sites will surely suffice! Sometimes, those "1,000 search engine" packages include spammy and/or malicious search engines, that will either hurt your site's reputation or attract harmful bots or scripts to attack your site.
• Some people prefer to get their site(s) listed on search engines by putting a link to them on an already indexed web site. This is also a good practice, if you feel that manual submission would result in a long wait (this can be true in some cases).

Images and SEO 

• Name your image files accordingly. If you're displaying a picture of a blue vase, name the image "bluevase.jpg" or "blue-vase.jpg." This helps do several things: 1) associate the image with your content, 2) add to the overall idea of what your page is about, 3) give you the chance of having your image appear in an image search, which may bring in many unique website hits.
• Include ALT & TITLE within images. These two attributes, along with your well-named image, will help your image rank for services like Google Images.
• Embedded image information. This has never been proven, but rumors state that embedding information within your images will help their ranking. This can be done through Adobe Photoshop (through "File" >> "File Info") or Adobe Bridge. By filling in the "title", "keywords" and "description" fields, you'll further justify what your image is about.

Targeting and SEO 

• Advertise your site to specific, relevant markets. Not only will it increase your website hits and possibilities of making more sales, but it will further associate your site with the theme of the site you're advertising on. Note that this purely refers to your link being added to another site, and does not count for pay-per-click programs (like AdWords). Pay-per-click advertising does not affect SEO in any way.
• Add your link to link directories, under the correct category. Link directories contain major categories (Arts, Computers, Jobs, Education, News, etc.) List your link under the most relevant category, to associate it with that category.

Ongoing Steps for SEO Success 

1. Update your website's sitemap whenever new content has been added to your site. If you don't have one already, create a free Google Webmaster account, which lets you update your sitemap with the click of a button. (If you don't know what a sitemap is, read Wikipedia's description. See if your programmer or website service can set up an auto-generating sitemap script for your website - since it is usually too much work to create one manually). Otherwise, use sites like XML-Sitemaps.com to generate one for you, for free.
2. Add new content on a regular basis! Don't forget to check all editorial in your favorite word processing program for grammatical and spelling errors before uploading.
3. Use an analytical program, like the free Google Analytics, to check your daily site performance. By using this invaluable marketing tool, you can further enhance your site by seeing who is visiting, and what they are looking for. In turn, tweak your site according to those results to make it more helpful to both people and search engines. Don't be afraid to change your META title, description or keywords if you deem it necessary.
4. Constantly work on getting more and more backlinks to your site, especially from websites that are in the same category or industry as yours. Make a personal goal - 1 new backlink per day, etc. The more, the better!

SEO: How do I... 

• ...promote or improve the rankings of my web pages - their URLs aren't SEO friendly! There are two main ways to do this: 1) URL re-writing will allow you to point those nasty looking links toward whatever you specify. 2) If this is too much work to do (and it usually is, for large sites), you'll have to promote your backlinks wisely. Create backlinks that have nothing but your valued 1, 2 or 3-word keyword as the URL, and point it to the page you want to promote. Do this as much as humanly possible. Make sure your title, keywords and description for the page match that term, as well.
• ...know if someone has stolen my content? If so, what can I do to stop them? First, use a free service like Copyscape to search for duplicates of your content elsewhere on the web. If they exist, you'll want to file a DMCA report with Google to proceed with their ban from search engines, if you are successful in the ruling.
• ...prove that my website was live on the internet during such-and-such date? Visit Archive.org - it showcases what websites have looked like since the mid 1990s. It's a great resource, and held in very high regard as well!
• ...contact Google? Find their email addresses here, or give them a call at 650-253-0000. Google is known for its excellent customer support - especially for users of their services AdWords, AdSense, Webmaster and Analytics.
• ...know if my site has been penalized from Google? Google has various penalties. For instance, the Google -50 penalty pushes your link down 50 spots. So, if you were ranking #2 and get the Google 50 penalty, your site then becomes ranked #52. This also counts for natural searches for your own domain name, itself. The only real way to check this is to type in "site:www.mydomain.com" in Google, and see where your site is ranking. The more severe the penalty, the further down you go. The remedy is to immediately spot and fix whatever has done this (usually, people who have done underhanded things to rank higher already know, or may have been ready for such an occurrence).
• ...know if my site has been blacklisted from Google? Visit google.com and type in site:www.yoursitename.com, or, simply use this tool. If there are no direct results, your site either has not been indexed yet, or is blacklisted. To re-index your site, make sure you've fixed whatever problem has gotten you banned in the first place, and re-submit it.

SEO Checklist: Reader Feedback 

Sofie8 Comprehensive and useful information. The tools are a great bonus. Amateurs like me are sure to extract nuggets of wisdom from this lens. Posted March 12, 2008

JanaMurray Great educational resource for entrepreneurs! Posted December 06, 2007

lionmom100 Thank you for this lens. It helps us SEO newbies. Lionmom100 www.squidoo.com/ILoveBANS-BuildANicheStore/ Posted November 23, 2007

becks9 Beautiful lens! Posted November 13, 2007

sieteram doing seo for your site can take so much time.. if you need to outsource, check out my lens for more information =) Posted November 06, 2007