Got a shit load of flack posting this is wow new player guides forum so figured I would share it here since I liked the spot so much and I lurk a lot.
My Original Thread: AOE Grinding Location FAST RESPAWN - Forums - World of Warcraft
Video: AOE Grinding WoW NorthRend DeathKnight - YouTube
And
Short text guide:
In Northrend, Dragonblight head to Galakrond's Rest and farm the mobs in the 4 small craters around the big crater with a skeleton in it.
They respawn in about a minute.