Feb 23rd 2010 9:08AM I just went through leveling Leatherworking and I must say that I found the following places invaluable:
Thick Leather: Sunken Temple - Just go in to the left into the dragonkin area. Easy to just AOE down all the packs and they skin for Thick Leather (sometimes dragonscales).
Rugged Leather: Dire Maul North - Down in the courtyard there are a ton of Gordok Mastiffs which drop 1-2 Rugged Leather each (sometimes Thick).
Knothide Leather: Black Morass - Just gather up crocs and panthers, AOE them down, skin, profit.
I did this all on an 80 rogue, so classes with better/worse AOE abilities and survivability may have more or less success.
Feb 9th 2010 12:23PM Sweet!