Instance: Drak'Tharon Keep
Box: 4x Ele shaman
Gear level: pre-heroic blues/greens(70 epics count as these)
Difficulty: easy(some deaths, no wipes)
Guide: <easy to read and not too long walkthrough of the instances, preferably including how to handle trash mobs, specifically

Trollgore
Basic tank and spank. He does a Corpse Explode which needs your tank topped off prior to it happening. Make sure tank is topped off before you heal yourself. Burn him down otherwise.

Novos the Summoner
Probably the hardest fight in the instance but still not that difficult. Have your tank round up the adds coming down the stairs, use an AoE to blow them up when it gets to be a good sized amount but focus on the single 4x Elites that come out with fairly low health and are casters. Once you can attack the boss, he just throws out Frostbolts, it takes 3-4 of them on the same targets to drop anyone so healing through it is very easy. Groundings do not work though, so stay close to the tank and Chain Heal if the damage is spread well or top whoever off needs it. Besides that he will do a Blizzard, when he starts casting the spell just begin run any direction to avoid it and rinse/repeat. Avoiding the Blizzard will save a ton of mana and you can take your time on this fight.

King Dred
Big Dinosaur that is a tank and spank that is ezmode if you have a Shaman in your party or a way to break fear. Basically throw down a staggered set of tremor totems and his biggest issue of AoE fear is negated. He will summon and add that your tank picks up. Just burn him down though.

The Prophet Tharon'ja
Very easy fight, his damage isn't that crazy and you go into a skele/ghoul mode with a new action bar about half of the fight. Spam the 3rd and 4th button whenever they are up, one of which is a nice damaging lifetap. Avoid the green puddle on the ground and taunt which is the second button if your tank is getting low. Top him off as you switch back into normal mode, it's not a very intensive fight.