Assembly of Iron: "Decipher THIS!"
This one gave us the most trouble that night, due to tanks getting insta-gibbed for various reasons (fusion punch + power rune, overload + power rune, fusion not being dispelled quick enough, etc). You may need 3 healers for this, and have the 3rd healer bounce between the two tanks to where they're needed most (and take over when you need a mana break!). The kill-order can vary; we did Steelbreaker -> Runemaster -> Stormcaller, which is reportedly the easiest. This is an endurance fight where survival should come first, and your mana will be stretched to the limit, particularly if the dispellers and interruptors don't do their jobs.
- Healing assignments will be necessary, as it is best to spread the tanks to either end of the room to minimize splash damage. As a resto druid, you should probably be with whatever tank has the current kill target so that you can reach the dps with WG (depending on your playing style, etc). There should be an interrupter with whoever is tanking Stormcaller, to interrupt his chain lightening and whirls and stuff.
- Steelbreaker: watch the incoming fusion punchs, as they cause a debuff that if not purged immediately, can deal maaassive damage to the tank. Time a nourish/regrowth cast to land right as the fusion punch does, and start spamming, dropping in swiftmend as necessary. When the tank's health isn't dropping in frightening numbers, you're probably in the clear until the next fusion punch. A paladin or priest must be in range of the Steelbreaker tank to cleanse the magic debuff from the tank. There's a small amount of kiting as well, as Steelbreaker must be moved off of the runes of power that the runemaster casts under him. You will probably be close to OoM by the time he dies (or even go OoM before), in Naxx gear. Use your innervate and keep on truckin'.
- Runemaster: At "Phase 2," Runemaster starts casting a giant green Rune o' Death. Anyone inside it must vacate immediately. Watch for people fleeing from it, they will need extra heals. This involves far more kiting as the death runes are HUGE, but you can probably place yourself in the center of the room and often then be in range to heal both tanks at the same time. The raid should still stay clear of Stormcaller's Overload, and interruptors must now watch to interrupt Stormcaller's Lightening Whirl. Try to get your hunters/shammies to put out nature resist totems/auras to help mitigate the massive damage the lightening whirls do, since thy have an immense range and deal massive damage to their random victims. This is the phase that you'll want to be letting your mana regen as much as possible.
- Stormcaller: At "Phase 3" he has all of his previous abilities (which still must be interrupted, keep after your interrupters!), plus he now has a flight phase, where he becomes a lightening storm himself and chases people around the room. Melee will have to run away quickly, but are likely to still catch some, particularly if they're being chased first, so drop a WG on the lot of them as they begin to scatter. Stay clear of Stormcaller yourself, and give yourself plenty of room to run if he decides at any moment to start chasing you. Your HoTs and swiftmends will serve you well in this part.
Freya: "Forgive me."
Kill the 3 mini-bosses unless you want to activate hard mode ala Sartharian + Drakes. Each of the mini-bosses requires some amount of kiting to escape the boss being healed (Brightleaf), or destroying your tank (Stonebark). Ironbranch may one-shot a few players with the roots damage or the giant impale thorn (which is not removable, like Najentus' was). When you engage Freya herself, she will spawn a wave of adds once every minute, to a total of 6 spawns. It comes down to a matter of killing the adds and surviving these 6 minutes, rather than doing any damage to Freya herself during this time.
- "The EVIL trio": a snaplasher, water elemental, and a storm lasher. The tanks will need to monitor debuffs on the snaplasher and tell dps where to go, as the snaplasher gets more powerful with every hit, and can destroy your tank. The Snaplasher's damage buff resets after 4 seconds. The elementals have a knockback: if you get hit by it, just run back to the group.
- "BOMBS": aggroless little buggers. Everyone (you included) needs to run in on Freya to gather them up. Let the HoTs fly around the raid, and don't let your raid become overzealous while killing them: each one explodes when it dies, and with everyone clustered up, that's some massive raid-wide damage. Call out when you need DPS to stop so you can catch up on healing... or have an appropriate raid leader call it out.
- "Shrooms!": a giant tree-man for the DPS to play with, and a blanket-effect silence that is only dispelled while sheltering by one of the many mushrooms he spawns in the area. Run to one immediately so you can continue healing. The mushrooms slowly grow to maximum size, then will wither away quickly. Any size of the spawned mushrooms will protect you, but be mindful of its growth and be ready to move to a new one. The tree also casts a lightening bomb "Nature's Fury" on a random player which will damage anyone around them; they must move away from nearby players. This may result in some rearrangement of players among their mushroom shelters.
- Phase 2: tank n' spank with some kiting away from the giant green pools of boss-healing. Easy stuff if you killed the giant tree minibosses beforehand. If you reach this phase, you've pretty much won.
Hodir: "Winds of the North, consume you!"
I find this fight a lot of fun, as a resto druid. Lightly plant yourself on one side of the boss, within range to heal the melee/tank; have your co-healer plant themselves opposite so they can reach any ranged dps on the other side. Keep moving: taking slow, jolting steps to break the stacking frost aura debuff, since each single movement you do will only remove one of the debuffs, and you'll have to stop and move again to remove any others that have stacked.
- Turn on Projected Textures in your video settings tab. Have everyone in your raid turn this on, it is very important. It will enable you to see the runes on the floor that show where the next set of ice shards will be falling from the ceiling.
- Ice Shards/Icicles: move out of the runes cast on the floor. Just pay attention to what's under your feet/roots.
- Biting Cold: press w to not die. This is the stacking debuff aura I mentioned above.
- Flash Freeze: when he begins casting this, two larger icicles runes will appear somewhere in the room: move over to them, but don't get on them until the ice has landed and created a snowdrift. Get as close to the center of the snowdrift as possible before he casts the freeze, as it may lag or bug and you'll still get ice blocked. You can heal any players who are trapped in ice blocks, but they'll need to be rescued by your dps.
- Freeze: a frost-nova type ability that traps your feet. As a druid, you can either wait for someone to dispel you (priests need to be mass-dispelling this, pallies can help with hand of freedom, and there's an NPC that somewhat assists), or shift out briefly to break it. I usually opt for the shifting-out.
- Frozen Blows: this is the one thing that can possibly wipe your raid, and the reason why you want the healers spread out to either side. Raid-wide damage ticking rather quickly, particularly if dispels are not being handled properly. Hand of Freedom (from pallies) should be kept on the tank during this time, else they'll be taking MASSIVE damage. Let WG take care of the melee, and keep an eye on all of the ranged players, and don't let yourself get distracted from the ever-spawning ice shards.
Have fun :D