Aggro management starts at home (if you're a warrior, thats you! ... paladins too ... but I don't play one, and I didn't stay at a holiday inn express last night ... so you holy knights are on your own other than the obvious Christmas song plug...). There are things a warrior needs to know to be effective at holding aggro. There are also things that a warrior needs to make sure his/her group knows about aggro management. These things aren't too important in ... say... Scarlet Monastery... but in the end game instances they can be the difference between phat lewt, and a corpse run that ends with the words "gah! respawn".
What you need to know: Taunt works differently in WoW than in previous games. It doesn't insert you in the aggro list above everyone else, or add some mystical amount of aggro that may or may not put you on top of the list. It's a debuff ... it forces the target to focus on you for 4-6 seconds. It even has an icon that will show up in the targets debuff bar. Once it wears off, if you haven't built up enough aggro to move to the top of the list, the target will revert to whoever is on top of the list.
What your group needs to know: In addition to the above, your group (and you) should be aware that the most recent taunt will overwrite prior taunts. So if your group's hunter has Piddles the cat set to a mode that will use growl, it can (and will) overwrite your taunt. Sometimes this is a good thing (pet is off-tanking), sometimes its not (most boss fights). Be aware.
When you should use taunt: Taunt is *snap* aggro. It will immediately turn something's attention to you. In most cases you want to use it only when someone other than you is being attacked. If the priest is getting skewered by an add, turn and taunt it. Hit it a few times, and then revert back to what you were fighting (or don't).
Advanced Taunt Tip: In some fights, heals and/or special attacks from other party members will come early in the fight (high dps bosses are a great example of this). In these cases, it's not a bad idea to use taunt as the person starts to cast/engage/etc ... Since taunt has a duration (4-6 seconds) this can keep the npc focused on you for a few extra seconds so you can build up the aggro to stay on top of the list once taunt wears off. This takes some understanding of the situation though and your group members. The last thing you want is for taunt to wear off just before greater heal lands, and you need to find some way to get A_Giant_Duck_of_Doom off the party priest in a shorter time than the 8-10 seconds till taunt is refreshed.
What You Need to Know: Hitting stuff first makes a difference in the aggro list, especially when dealing with healing aggro, and to a lesser extent AE situations. Why does it work this way? I don't know. But you'll have better luck keeping those late adds off the druid/mage/whatever if you tag them before someone else does.
What Your Group Needs to Know: This is important, so I'll give it its own section in a moment... the tank will be switching targets a lot on pulls that involve more than 1 npc that isn't crowd controlled. This is important because if the rogue assists early, and the hunter assists late, suddenly they're killing 2 different things... which is inefficient and an aggro nightmare.
When to Hit Stuff First: If it's not a boss fight, try to tag anything that isn't being frost trapped/polyd/sapd/etc... Be careful though... if you keep smackin the npc that your mage is trying to sheep, neither of you will be happy, because the mage is going to get aggro, and you're going to be at fault. So plan ahead, and pay attention. Same goes with frost traps... wait till they've been triggered before whackin stuff.
What You Need to Know: This isn't EQ. Repeat that statement a few times. Ok... in WoW, especially in later dungeons, the average pull will be somewhere between 3-5 npcs. Sometimes a group will be in position to crowd control several of them, but there WILL be times when you're fighting multiple elites at one time (and whole flocks of non-elites). Don't panic (you remembered your towel didn't you?). If you're the only tank in the group, your job is *NOT* focusing on one target until its dead, then switching. Your job is keeping the rest of the group from getting cooked faster than Emeril can say BAM! This is a change from what you're used to. In order to aggro multiple targets you need to (stay with me now), switch targets. When the pull first comes in you'll need to whack one thing (usually the groups preferred target for death) a few times... then you should switch. Hit something else (something that isn't freeze trapped, poly'd , sapped, or succubused). Tag it a few times, maybe drop a sunder armor or concussion blow, and move on to the 3rd target, and 4th (if there is one). Yes, it sounds crazy, but your healer will thank you for it. Why's that? Well... when all the dps *and* the tank are focused on 1 npc... who will the other 2-3 npcs aggro when that first greater heal lands? It's safe to say the squishy cloth wearer in the corner will look mighty appealing to the bad guys. If you've hit each of them a few times, it's a LOT less likely that they're going to go chew on your healers hind quarters. If one of them does, see the taunt section above.
What Your Group Needs to Know: Your group should assist someone other than you for targeting. No, it's not crazy. Seriously. There's a reason hunters get hunters mark, and its not to annoy rogues in PvP. It doesn't have to be a hunter either... rogue, paladin, the other plate wearer (if there is one), shaman (if not the groups healer), etc ... Pick someone... someone other than you. If they're all cloth wearers, you'll have to keep an eye on that targets aggro ... but if there's some mail classes, or even a rogue... the healer can spare a heal for em... really... so long as you keep the rest of the pull busy. What will happen if your group assists you? Well... they'll end up on different targets, since you're switching around to control aggro... which means that if you lose aggro, it won't just be on the primary target, it will be on 2 targets... which means the healer will have to heal 2 other party members, plus yourself... that's going to make the healer aggro ... which is exactly what you were trying to avoid in the first place. Seriously.
Cautionary Notes: Switching targets only applies when there are a large number of targets, and at least 2 aren't being crowd controlled. You should be able to keep 2 busy with cleave and demoralizing shout ... more than that ... switch, hit, switch ... but do NOT NOT NOT break frost traps, sap, polymorph to do so. Seriously... if I get a bunch of mages sending me tells "our tank keeps breaking poly and says you told him/her to" I'm going to lay some smack down... for emphasis switch targets, but do NOT break crowd control effects such as polymorph, frost traps, or sap to do so. You may now return to your regularly scheduled aggro management tutorial.
What You Need to Know: Per above, you'll be getting more than 1 npc per pull in most dungeons. In later dungeons it will actually matter that these extras aren't churning your healer into butter. Several other classes have crowd control options... but *most* only affect 1 target at a time. What this means is, you're going to have more than 1 target to keep busy. An effective way to do this is using multi-target attacks. Cleave should be in every hotbar you own. Use it. Just use it away from the sapped/poly'd/trapped npc. Demoralizing shout is fantastic, because it pushes you up the aggro list, and DOESN'T BREAK crowd control effects. Whirlwind (which requires berserker stance) is good for mass pulls of non-elites in mid level dungeons. In later dungeons, there will often be elites along with the crowd, and whirlwind is less effective at getting those focused on you. Cleave, Demoralizing shout, use them... excessively... just DONT BREAK SAP/POLY/whatever. Oh, cleave faces forward... remember that. For AE-pulls, also throw down a thunderclap... yes... thunderclap... stop laughing and go use it already.
What Your Group Needs to Know: The only group responsibility here is to try to keep the fight away from the crowd-controlled targets... or the crowd controlled targets away from the fight. If you're hitting cleave non-stop and the group's mage tries to poly something you're fighting up close, its not going to go well. Keep "controlled" targets away from the action.
What You Need to Know: Not all warrior attacks are created equal. Some attacks build *far* more aggro per rage point spent than others. Here's the list: revenge, overpower, shield bash, concussion blow, and sunder armor* (with the last patch, sunder armor appears to have taken a hit to its aggro production ... still worth using though). What this means to most warriors is simple... use overpower/revenge every time they come up. Stack sunder-armor up to its 5-use max (you can stack up to 5, in case you didn't know that), and shield bash and concussion blow are great aggro-grabbers when taunt is down.
What Your Group Needs to Know: Nothing... knowing to use these is basic warrior stuff, and doesn't impact your group at all.
What You Need to Know: Warriors have multiple "snap" aggro effects. Taunt, Mocking Blow, Challenging Shout are your primaries here. It's important to note that Mocking Blow requires battle stance, while Taunt requires defensive stance. If you have tactical mastery, you can stance-dance to take advantage of both (also good for arms/fury folks to dance->overpower and back to def stance). What "snap" aggro means is that for a short duration (usually 4-6 seconds) that npc will *only* attack you (provided no one else throws down a taunt-like effect). Use these to get npcs off of healers/casters, etc ...
What Your Group Needs to Know: Similar to the taunt discussion above, its important to know that snap aggro doesn't permanently move the warrior to the top of the aggro list. Classes with escape abilities (fade, FD, etc.) should take advantage of the 4-6 second reprieve to move themselves down the aggro list.
What You Need to Know: While in defensive stance, your attacks generate more aggro than they do in battle or berserker stance. Yes, you do less damage, but you'll end up with more aggro despite the damage gap. In an instance run, you should be in defensive stance anyway. Mortal Strike does NOT require battle or berserker stance... so even arms/fury warriors have no excuse for not being in defensive stance for hard parts of instances.
What Your Group Needs to Know: Nothing, nada, zip
What You Need to Know: Unless there are multiple plate wearers in the group, you're not along to do damage, not there for your good looks or high standard of dental hygiene ... you're there to take damage, absorb damage, and stop npcs from picking their teeth with your party's warlock. Yes, it's great when you mortal strike for 1600 with that giant 2H axe you have strapped to your back... but you're in an instance run now buddy... suck it up... strap on a shield and pull out something that loosely resembles a one-handed weapon. Why do this? Simple... healer aggro, and special shield abilities. With a good shield equipped, you will take roughly 10% less damage just from mitigation... that doesn't even count blocked damage. Less damage means less healing. Since you're the target of all the npcs (except maybe the one the group is killing)... 10% can be a HUGE savings on health and mana. Help the healer help you. Second, shield bash interrupts spell casting. This is huge when the other side has a nasty healer in their midst. Play whack-a-mole with the enemy priest/druid/paladin using your shield... it's also a *great* aggro generator, even if they're not casting at the moment.
What Your Party Needs to Know: There will be times when it makes sense for you to break out the giant Conan Axe, or put the shield away for an off-hand weapon... such as large pulls of non-elites... or when you want to impress your significant other looking over your shoulder with "look honey, 2150 critical hit!"... as long as these times aren't during important pulls (such as level 58 named lava giants), your group can probably live with it. If you insist that there's no reason to put away that giant 2H mace when fighting Ras, Rivendare, or Rend... well... your group needs to know that its time for you to go.
In summary:
1. Understand How Taunt Works, and use it
2. Hit stuff first (just don't break poly!)
3. Switch Targets (just don't break poly!)
4. Use Multi-target attacks (but for Pete's sake, DONT break poly! ... or sap, banish, or frost traps).
5. Use aggro-heavy abilities.
6. SNAP aggro is the warrior edge.
7. Defensive Stance ... use it!
8. Strap on a shield.
Also check out this flowchart for basic tanking. It won't get you through everything, but it'll get you on the right track!
