For me i was just wandering along and stumbled into this gold mine of leather. Down in STV there is a cave full of crocs. Its just south of Mosh Ogg Ogre Mound. They are level 42-44 crocs. It is very big inside the Crystalvein and you will surely never run out of mobs to kill. Not many people there after hours of farming, one of the best spots for this, Horde will have a easier run there than alliance.
I will post more leather areas as i level with it
<---- Brinek Tauren Druid 70, Guild:[Sin] Server:[Icecrown]