Installing vinyl siding

Siding is sold by the square. One square is 100 sq feet which will cover an area of 10 feet by 10 feet. To figure the amount of siding you need, measure the square footage of wall space to be covered and divide by 100. This will tell you how many square you need.
Starter strip is used under the first row of siding to hold the bottom. Measure the perimeter of the building for the amount of linear feet of starter strip needed.
Next you need out side corners. This is figured simply by measuring the height of your buildings corners.
Next is J channel. J channel is installed around all windows, up rakes and under eves. If you have a chimney the J will run along the edge. Anywhere you need to end siding other than corners will need J channel. J is measured by the linear foot.
Undersill trim is used under windows to cover the cut edge of the siding. It is also used inside the J channel at the eves to cover the edge of the last piece of siding.
Aluminum nails are used for nailing siding. A couple pounds of siding nails will go a very long way. Roofing nails can also be used to install siding.

The first thing you need to do to prepare for installing vinyl siding is to get your surface ready. A house wrap like tyvek is highly recommended. Foam can also be used under siding and you will benefit from a bit of insulating value.

To start you need a level line all the way around the building that represents the top of the starter strip. Mount the starter so that when your siding hooks into it the siding is slightly below the joint between the foundation and the framing. You can do this with a transit, lazer level or even a line level. Whichever method you choose be sure this line is straight and level. The whole job depends on it.
Chalk vertical lines on both sides of your outside corners. This represent the nailing flanges on either side of the corners. Don't skip this part. Nothing worse than a newly sided house with crooked corners.

The first step is mounting the starter strip. Be sure you mount the starter so that when the siding is clipped in it ends up slightly below the house framing just covering the concrete. Keep the strip 1" away from the corner nailing flanges and leave a 1" space between pieces when joining two together.
Install J channel around all windows, up all rakes and eaves and anywhere you need to stop siding like around a chimney or electrical meter.
When installing the siding be sure to lap your joints away from the traveled areas. If the joints are lapped away from you you won't see them as much. Lap joints about 1".
When nailing siding don't stretch it but hold it up from the bottom and nail it. Siding that has been stretched will wrinkle badly especially as the sun hits it. Don't drive your nails home as this will also wrinkle siding. Leave the nail heads back 1/16" or so. When siding ends either in a corner or a J leave it a little short to allow for expansion and contraction. Siding moves a lot more than you would think.
When you get to the bottom of the windows you will have to cut the siding and snap it into the under sill trim. You will need to use a snap lock tool to put a small divot on the edge of the siding in order to make it snap together. Anywhere you use under sill trim you will need to use the snap lock tool.
As you side up the building try to keep the joints as far away as possible. A general rule of thumb is to keep joints a minimum of 3 feet away with a full row in between.
These are just a few basic rules I can think of. Every box of siding has full installation instructions. For best results and to protect your warranty follow all the manufacturers instructions.

When shopping for siding don't compare prices by the price of the siding itself. First off there are a few different grades of siding and you need to compare apples to apples. Secondly, The price of the actual siding itself is not where the bulk of your money is going to be spent. It's everything else like starter, J-channel, Corners etc. that actually cost the most. You can spend less on siding but depending on the price of the extras you might spend more in the long run. The stores trick you into thinking their siding is the cheapest but it may not be. It's best to price everything before deciding who to buy from. The difference can be substantial.