Instance: Azjol'Nerub
Box: 4x elemental shaman
Gear level: 80 blues, some 80 heroic epics start to build up too, mainly on one char however only.
Difficulty: normal but with a learning curve.
Guide:

Before you start, bring mana potions. You will definatly need them!

The Three watchers and first boss.
Kill the watchers first, then the two adds they have. The watchers themselves are most problematic. All the while don't use mana intensive spells. Stick to Flame Shock, Lava Burst and Lightning Bolt on the watchers, and only Lightning Bolt on the adds. Kill the watchers asap, then take it slow on the adds. Make sure watershield and mana spring totems are always up. End boss, just nuke him badly, stick close to the tank, when adds spawn, Thunderstorm and Fire Nova Totems and finish off the boss. Down a mana potion at any time when you get below 50% mana.

The second boss
Mana will defi be a problem here, I wiped here twice due to running out of mana. It is essential to be as mana conservative as possible. This means you kill the big blue ones quickly so you don't have to heal too much. Then LB down all adds, also make sure you kill the occasional add that runs to you. When you do so, you might get a moments rest to drink up. High dps is essential. If you take too long over a pack, the next pack will instantly aggro you when you kill the previous one. However if you kill the packs quick enough, as well as the loose adds that run to you, you might get a window to drink. This happened to me on my last go before the last pack, which was key for me in beating this event. Last pack I killed asap as well, I didn't get a chance to drink this time, however with swallowing a runic mana potion I had enough to kill the boss. Here's a few important things. You need at least one poison cleansing totem up. Preferably more, but depending on your mana situation, 1 with 3 mana springs might be enough. A disease cleansing totem will help on the adds before as well by the way, I myself just dropped disease with my main followed by mana spring again whenever needed. And had one alt drop poison cleansing totem, two others mana spring totem. When the boss is spitting poison to you, run away and chain heal (heal tank first if he's low. :P ), and continue dps. Again, Flame Shock + Lava Burst + Lightning Bolt only for mana conserving. Don't use chain lightnings unless you believe you can afford them.

The last boss.
This is a bit of a problematic fight, trust me. The boss itself is piss easy, he doesn't do much damage at all, it is the off phases you need to worry about here. Every 25% he will dig in the ground and adds will spawn. And the boss will sometimes ruffle up the sand and then stick his hiney through it. When he does and you are on it, 7k damage on you as well as some falldamage. You need to avoid these, all of them. To do this best is by spreading out and have individual movement forward and back keys. When you see the ground rumbling under on of your chars, move forward with that char alone, so your other three can continue healing/dps. The first off phase seems easy, the second and third however seem to have an increase of add spawns. (Might be me.) Use flame and/or earth elementals in those phases, preferably the last off phase. Or one of each in the last two off phases. It will help a lot to do this. It's very intense, but you will get breathers whenever the boss is back, don't dps the 25% too quickly if you think you need some time to prepare for next off phase.


All in all the instance is quite doable, but the last boss does require multiboxing intensive control to beat.
Wipes.
I wiped twice on the second boss due to running oom. I solved that by finding the right dps strategy.
And twice on the end boss myself due to getting too much damage on me, by spikes, and either losing the tank or running oom because of having to heal too much. This I fixed by controling my char movement better.