See that mob? He sees you. He sees you rollin'. He hatin'. Which is exactly what you want! Excellent. So you hate right back. You've got him mad, so mad! And all of a sudden, all that mad.... well, he learns how to punch you in the head REALLY, REALLY HARD.
This is where you scream "Oh God My FACE!!"
First, let's take a look at defensive cooldowns. These are the cooldowns that will keep you alive. In every bear's toolkit, there are a whole bunch of little things that are powerful on their own, but when used in the right combinations, make you utterly unkillable.
Frenzied Regeneration is an ability that works like a warrior's Bloodrage, except in reverse. Meaning, it takes rage you have, and converts it into health. This ability is best used when you have plenty of rage, as it won't make health from nothing.
Survival Instincts raises your max HP by 30%, and raise your current HP to proportionally the same value. When the effect ends, the "bonus" HP is lost, but your current HP stays the same, unless it is over your normal max HP value, at which point it will just become your max HP.
Barkskin reduces the damage you take by 30% and also takes away spell pushback. Since bears don't cast spells, the pushback doesn't matter for us too much. But, the 30% damage reduction is great.
Those are the talent cooldowns in your toolbox in bear form. There are more cooldowns to think about though, in addition to these.
Potions! Bears should eat Indestructible Potion like they're candy. Because they are candy. Delicious, bear-food flavoured candy. Indestructible potion increases armor by 3500 for 2 whole minutes.
Healthstones! If you have a warlock in your party you must make them give you candies. All the time. Don't worry, they're used to it. A healthstone, realistically, gives you the option of popping an indestructible potion and a health potion at the same time.
Trinkets!! Trinkets are very important, because most of the higher-end trinkets have a use ability that will either increase armor, increase dodge, heal you, or something else useful. When blowing cooldowns, it's best to use a trinket with a combination of other cooldowns so that its effect is best enhanced.
If you're an herbalist, you get one last cooldown to play with: Lifeblood. Lifeblood is a self-cast HoT that doesn't break bear form. At rank 6, it heals for 3500... but that increases in proportion to your maximum health. So it stays about as powerful, no matter how geared you get.
Now, there's a few options for using cooldowns. There's the "use every single one as soon as you can" philosophy, which will make you look like you're just naturally super OP. Another one is to write a couple of long "oh shit" macros, one, two, or three... depending on how many times you anticipate needing them. Another is to communicate with your primary healer intensively, and use your cooldowns in conjunction with theirs, which effectively makes your cooldown toolbox that much bigger. I'm a macroer. Here are the macros I wrote to blow my cooldowns in 2 separate buttons: one blows all my cooldowns that up my mitigation, and one blows all my self-heal cooldowns. I'm an herbalist, so I have lifeblood, so, if you want to use my macros and aren't an herbalist, just take the lifeblood line out.
My macros are:
/cast indestructible potion
/cast survival instincts
/s can't touch me!
/cast Fel Healthstone
/cast Frenzied Regeneration
/y OW MY FACE!
I put the /s and /y lines in to make sure to let my healer know I've done a little bit to try and make it easier on them, either because I know a lot of damage is incoming, or they need to concentrate on keeping either my offtank or the rest of the raid up through lots of AoE.
So that's defensive cooldowns. As a tank you really only have one offensive cooldown, which is Berserk. This causes your Mangle to have no cooldown, and makes your mangle hit 3 targets instead of just one. I like to use this when we bloodlust, because mangle is the highest-threat move I have, so it gives me a little bit easier a time hold threat against a bunch of bloodlusted dps.
And that's about what I have to say about that.