ToC as a Tree
Boss 1 - The three stoo..rrr..champions.
You start the encounter om a horse, jousting away. Not that hard, if your horse dies, get a new one. But now comes the catch, if all three champions are down at the same time, everybody will dismount to start an 'old-school' encounter. But...there's a 75% chance you will die after dismounting. Because the three bosses are probably spread out, it takes some time for the tank to pick them up, throw ONE heal, and you get aggro from something that WTF-pwns you. Hope you get a paladin who throws a BoP.
The healing is very heavy at the beginning, sometimes poisons are being thrown around, so just go all out, let Rejuv tick on everyone, use Wild Growth continuously, and nourish/swiftmend the tank. when one of the bosses is down, you can relax a little.
Boss 2 - Either a Pally, or a Priest
The Pally-Not that hard, mostly normal tank healing. He will stun (hammer of Justice) and damage (Hammer of Wrath) one party-member sometimes. But that can be easily healed up, mmm, HoJ is magic, maybe a pally can cleanse it. The other ability is an AoE-blast which will take everyone down to around 40% health.. if they are looking at the boss... your character for that matter, so you can turn the camera around, as long as your toons back is to the boss (tanks should run through them). Be prepared that some PuGger won't turn around (loose of their Imba-DPS), so be ready to throw a nourish.
The Priest-Ok, the priest does VERY LOW melee-dps, I read somewhere she can be tanked by an enhancement-shammie. She does however throw a lot of Smites to random members. So very easily healing, if she is alone. She however summons a past Nightmare (Hogger/Prince/Onyxia and more) which makes the figh more interesting. The add should be tanked/killed as soon as possible. Why? Because he does an AoE-fear.. so keep rejuv/Wild Growth ticking on everyone, because he sometimes forgets the tank. If he is down... time to relax...
Boss 3 - The Black Knight
Hey didn't we.. oh well. I'LL BITE YER LEGS OFF (sorry :p). This encounter has three phases, in which you need to heal differently. In the first phase, he's a wimp. A Rejuv for the Tank, and a Wild Growth for some minor AoE damage is all you need. There will be an add jumping around, so a rejuv on yourself could come in handy.
Second phase is different. He know has about 10 adds, so hug the tank so his AoE-threat will keep the little buggers of you. There's a lot of AoE in this phase, but not that much direct-tank damage. So Wild Growth/Tranq will help you, together with a Barkskin for healing-aggro in the beginning. But... don't stay to close to the tank for long. The Black Knight will explode his adds, doing a lot of damage, and probably one-shot you. Don't worry if one or two adds will follow you away from the tank, even if they explodem it's survivable.
The third phase has no adds, just a Black Knight hitting very hard, so focus on Tank.
Gratz with you 3 Conquerer-emblems, 3 Champion Seals and some Tier8-gear (Ilvl219) if you did this on heroic, else gratz on the Tier7-gear (Ilvl200) (and maybe some PvP-emblems). Only difference between the two difficulties is that the bosses hit harder on heroic.
Oh, and if you are dead.. run back. Graveyard is very close, and you can run in... any dps begging for a Brez should be laughed at. Typing the sentence and finding the time to cast it, takes longer then running back.