That Tanks the Cake

In Frost Presence all your spells generate 2 times the threat(2.08 to get closer to the math). Stay in it while the MT or the OT. (main tank and off-tank respectively)

Good Glyphs to take, I use Unbreakable armor Glyph, Ice Bound Fortitude Glyph, and a good one to start with is Glyph of Howling Blast. (adds Frost Fever to all targets when hit with Howling Blast) Again use different ones, experiment, what ever fits your play style. Blizzard always seems to force us to go one way if we want to be the BEST OF THE BEST! Worry not, the best is only a bit better then the rest. You can probably still play how YOU want and be close to the current "best" play style. As long as you are not just doing everything in your power to throw out more death coils(as frost) or something silly like that.

Talents and how they effect you.
Blood tree - Blade barrier 5/5 - 5% less damage.
Two-handed Weapon Specialization 2/2 - 4% more damage.

Unholy Tree - Anticipation 5/5 - Dodge 5%
Epidemic 2/2 - Disease's last 6 seconds longer
Unholy Command 2/2 - Death grip Cools down faster, Better threat
control(may also want to go with Morbity)

FrOsT---
1. Toughness 5/5 -15% Plus armor. Not slowed as long. I cant really explain it better. :)
2. Improved Icy Touch 3/3 - This will decrease enemy attack speed 20%.
3. Black Ice 5/5 - More damage equals more threat generated.
4. Icy Talons 5/5 - With this plus Improved Icy Touch, you slow the damage down and speed yours up. Win+Win! But if you feel you can use points better somewhere else this is a good spot to draw points from. :) I would honestly put the points into Blood of the north 5/5. But I put it here in the spec for you to play with and not feel like it NEEDS to stay there.
5. Lichborne 1/1 - Nothing worse then the Tank being Crowd Controlled by the Raid boss.
Plus if you target yourself and cast Death coil while "Undead", you heal yourself with it. :) Macro for that on macro page!
6. Annihilation 3/3 - 3% More crit chance, and Obliterate does not strip the target of the
diseases. Which is needed to get the effect of Tundra stalker and Glacier Rot.
7. Killing machine 3/3 - More Crits again. More damage. More threat. You want to burn
your runic power, Frost strike is the tool to use....this makes FS a critical hit.
8. Frigid Dreadplate 3/3 - Makes Melee 3% less likely to hit you. Damage mitigation.
9. Glacier rot 3/3 - 20% extra damage with HB, IT, FS when target is diseased.
10. Rime 3/3 - More crit but the biggest reason to take this is the Freezing fog. Which resets the Cool down on Howling blast and cost no runes. A good, Free, Damage dealing spell and Threat Gen.
11. Improved Frost presence 2/2 - the extra 2% less damage makes keeping you healed easier on your healer. Also, 2% is not that much if you need two points here is a good spot to pull from, IMO.
12. Unbreakable Armor 1/1 - Your bread and butter. In a raid, popping this can keep you alive in very bad situations. Damage mitigation is very important to a tank. this gives 20 Seconds of Fantastic mitigation.
13. Blood of the north 3/3 - More damage from your FS, BS and death runes!
14. Acclimation 3/3 - Once stacked, three max, makes you very resistant to a Spell school.
15. Frost Strike 1/1 - with Killing machine makes this hurts very bad. And gens good
threat.
16. Guile of Gorefiend 3/3 - Bonus Crit damage yes, But the extra six seconds of
Icebound fortitude is the real reason you want it.
17. Tundra Stalker 5/5 - More damage, and Expertise lets you hit more and hit harder.
18. Howling blast 1/1 - Lots of Damage, Lots of Threat. With Glyph of Howling Blast once HB grabs the Aggro of the mob the frost fever ticking on it will keep increasing the threat you gen on it. On top of that when blood boil hits a target it does more damage if that target is effected with a disease. Howling blast puts Frost fever on all mobs it hits, two blood boils after that generates good threat. Use what ever works for you, I can not stress enough EXPERIMENT. But to help, the below rotation with Glyph howling blast, works pretty well.

HB BB BB OB FS.

With out Glyph of HB.

HB, D&D, BB(BS) then a disease rotation.

--UPDATE--As Zalt asked in the comments, Should they use Rune Strike, I answered it but started thinking, Rune Strike may not be something you actually figure out to use on your own seeing as there wont be a SEEN reason to test it out...SO Use Rune Strike every time it procs. As I am sure many Tanks see when using these Rotations and ideas, they see how you work threat, damage, TPS. They see that "HEY I just thought of a rotation that may work better!" Or "what if I work this ability into the mix?"I had hoped Rune strike would be one of those abilities. :( But alas. I fear there is no clear given reason to test it out beside shear curiosity and that is Procs. But some may view it as a DPS ability more than a threat generator.

Once You get familiar with the skills and abilities, what they can do, what you can't do. Experiment on a target dummy, on the mobs in Icecrown, Where ever. Even Try to open up tanking a boss, preferable a Heroic boss so you can see how the damage output is and the aggro hold of the shots.
With this rotation, you see many cause and effect situations. It will also give you some good ideas on how to maintain threat, and quick fix ideas while tanking, I find that many DK's forget to use Empowered Runic Weapon.

Cast Howling Blast, Lay out a Death and Decay. Blood strike(but if there are adds, Blood boil), Frost strike,

Then Cast Empower Rune weapon. Blood tap, Icy Touch, Blood Strike, Obliterate, Obliterate, If Freezing Fog Procs, cast Howling blast, if not(so long as you have Runic Power for Rune Strike) Frost strike. Starts the pull off with a lot of threat and Damage and it is fun to work my fingers a bit faster and pull some DPS as a tank. Those cause and effects, procs, Runic Power, Damage, TPS and, I love the numbers popping up on my screen. However.....

Your job is not to do damage, You are to just stay alive and keep that threat! there are times you may have to sacrifice DPS for Damage mitigation, so STILL pop Icebound instead of Frost strike if you are taking to much damage. Unbreakable armor is great to lead into a boss with(yes I know it cost a Frost rune and messes up your whole Rotation. If you are not Hit capped you may not be able to pull high damage because you will be focused on damage Mitigation...Which brings us too......

DAMAGE MITIGATION!!!!!
---Side Note---- Check out the Marco page for a few ideas on improving your Damage Mitigation.
Do Not forget to use
-Icebound fortitude- all the time. Last 18 seconds with your Guile of Gorefiend, the less time the healer spends on you the more the healer can spend helping with the raid heals. OR just regain mana for the enrage that so many Lich King bosses seem to have.

-Unbreakable armor- it has a 2 min Cool down. but for 20 seconds your healer will think OMG DID I JUST LAG OUT!

-Anti magic shell- 5 seconds of all magic damage being reduced by 75%, runic power generation increased, no harmful effects can be applied to your character.

-Improved Frost Presence- You take 7% less damage.

-Improved Icy Touch- enemy attack speed reduced by 20%, less attacks hit you.

-Acclimation- Gives you a higher resistance to spells of the type that just hit you, Stacks three times.

-Frigid Dreadplate- enemy's 3% less likely to attack you. stacks with Def. Doesn't make you less likely to be crit, just straight up less likely to be hit.

As I stated earlier, this is a good cookie cutter build I fully intend for you to tweek it to your play style, or mayhap this fits your play style. However you chose to enjoy the game, I hope this site made it easier for you to get your tank on. And as always....

HAPPY TANKING! :)