HEALER GUIDE
Since ET in general requires a lot of Rapid Heals, and rapid heals are the most inefficient heal (at the tradeoff being the quickest heal), you will run out of mana much faster than in other dungeons. So focus is on Wisdom, +Mana Regen, and then +Healing gear. You might need to DB yourself in ET, whereas in general you pot and DB the mage. So tell the mage to pot You got a tank to rapid heal, yo!
If farming first boss, there is a trick to do it without using much Exhaust. I learned this from Ruhz and I guess it's commmon knowledge.
Ranger stays outside till it's all done and sneak in. The goal is to get everyone to the "bridge" leading up the "arena" where the first boss fight takes place.
Mage casts the speed buff on the Tank, Mage, and Monk. Tank leads the way and aggro all the trash mobs, running towards the bridge.
Mage and Monk: You will "log out" when they get to the bridge (be sure not to die before you do this, else you have to start over). You "log out" by going back out to the Character List Menu. Wait a sec, and then log back in.
Monk: After logging in, ressurect the dead tank.
Tank: After grabbing aggro, stand there at the bridge and die. It will be a bit lonely for a while till they come back... Haha. Make sure mage and monk has logged out. DO NOT RESSURECT ON YOUR OWN. Wait for monk to log back in and rez you.
Ranger: Once tank is dead and monk and mage are logged out, go in, sneak your way to the bridge. (This is b/c you hvae to be out of combat to sneak).
Voila, you came to the first boss without clearing any trash mobs.
HEALER: FIRST BOSS(ES)
Ranger and mage will go to the right and DPS down the enemy healer. I cast restore on the tank and then go to the very right and cast my first Ring of Healing.
After that, I slowly move over to the left towards the center of the arena between my Ring of Healings. This is because the enemy warrior does that AOE Vortex Blade attack which can kill you, and it takes a few sec for him to move out of everyone's way and follow your tank now kiting him. He walks slow as hell, that's why. And secondly, you want to be closer to the center because that way you are closer to the tank when he returns from his kiting circle.
So I spam Ring of Healing and when tank is in range, I throw Rapid Heals (usually once if it crits, twice if not, and Restore if his Restore has expired). If the timing is right, you can heal the tank with the Ring of Heal (all 4 members) and then follow up with a Rapid Heal on him. Otherwise, focus on rapid healing the tank when he's running by.
Once the enemy monk is dead, move, with the mage and ranger towards the enemy mage. Same thing, Ring of Healing spam. You should be closer to the tank, so most of the time I'll get the tank with the Ring of Healing. I find that if I am Rapid Healing the Tank too much I'm pretty low on mana at this point. And our mage is probably low too. It's your choice, DB yourself and hope the mage pots himself, or DB the mage and pot yourself. It depends on how much I like the mage I'm grouped with <3
Sometimes, I'll also do a Prayer as soon as the tank is in range, as that will allow him to receive the Prayer heals as he runs by. And again, Prayer is the most efficient healing spell... However, if he's out of range and needs a heal, I'll interrupt Prayer to Rapid Heal him.
Some groups will DPS and tank the enemy ranger and warrior together, while other groups will have our ranger kite the enemy warrior while the tank and mage DPS down the enemy ranger. The second option is easier on everyone and on your mana, but of course can take a little longer since you are not DPSing the last two mobs together.
In either case, focus heals on tank only. Rapid Heals on tank. Occasional Ring of Healing if needed, but you shouldn't need it as these bosses don't do AOE damage (well, the enemy warrior does, but a archer and mage should not be in the AOE range at all). I guess a DPS warrior or Assassin Ranger would be-- then they should move out of the way and move back in. I've seen tanks do this too, move in and then move out when he's doing this AOE Vortex Blade. The Enemy warrior does hit pretty hard, so Rapid Heal on tank is important. I've also tried putting Prayer of Pure Faith into the rotation here, and it can work, as long as the tank isn't too low on HP when you start the Prayer. It helps mitigate damage from the Vortex Blade attack. But as you know, it heals in 1 second bursts, so if the boss crits your warrior he might not recover HP as quick, so it's a risk you take. I'm gonna say that if your +Heal is good enough and if the tank's HP isn't too low, you can use Prayer here if it's up. Else I'd stick with Rapid Heals.
And that should be it...
HEALER GUIDE - ET DRAGON
There really isn't much to say except this:
Phase 1: Start Restore on tank before dragon shows up. Then, nonstop spam of Rapid Heal on Tank. Ignore everyone else. If they die, oh well. DB yourself when you are low on mana, ideally when Tank is in Guardian Stance. Goal is to keep Tank's HP as topped up as possible.
Phase 2: Run up towards tank, Prayer of Pure Faith, then spam Ring of Healing. Probably don't need to rapid heal tank, as everyone should be getting evenly damaged by ice shower. DB the mage if you want, but priority is your mana, not the mage's.
Phase 3: Continue Ring of Healing spam (Prayer whenever it's not on cooldown), with Rapid Heal on tank every 1-2 Ring. Dragon will attack tank only and then AOE, so that's why you need to touch up. IF harpies appear, you'll need to hope that your Ring of Healing crits and Prayer is available... They will hit everyone very hard and it's worse than Cosmo's AOE... Possible wipe if you can't keep up with your heals... Towards the end of Phase 3, make sure tank has Restore active on him and his HP is topped up, because in the next phase it needs to be topped up as much as possible.
Phase 4: Like Phase 1, except the dragon stuns (no healing possible). Rapid Heal only the tank. Ignore everyone else. You have to ensure that his HP is topped up before the stuns. Coming out of the stuns (you should be spamming Rapid Heal even while stunned so that it starts to cast the nanosecond you come out of stun), Rapid Heal like there was no tomorrow. Throw in some Restore if you can, especially when Tank is in Guardian Stance (also a signal for your to DB yourself). When in a pinch, you can also cast Prayer as soon as you are out of the stun if your tank's HP is critically low and you need a heal to hit right away (Prayer has no cast time, that's why). Feel free to cancel Prayer by moving and then back to Rapid Heal to top up tank before next stun.
And when his stuns are done, Prayer and/or continue Rapid Heal spam on Tank (ignore everyone else).
Gear-wise: I go for the highest +Healing gear combo I have (2x Devout Mark in terms of trinkets for me... Mana regen be damned, b/c I'm going to DB myself anyways). Also, I started experimenting and instead of my Crystal Ring of Salvation, I use the epic spell crit ring from the soul vendor to get more Rapid Heal crits. I've seen +4500 rapid heal crits on tank (I am also specced in my tree to have Rapids crit/heal for more when tank's HP is very low), which is awesome and exactly what I want to keep him topped up.