This is where I go when levelling Skinner Twinks or when wanting for leather.
- Duskwood, right to the west of the Alliance Outpost (Darkshire?) are a few camps of hostile Worgen (Nightbanes I think they're called). They don't respawn as fast as the Terrowulfs in Ashenvale but there are enough of them (and their pets, some type of wolves) that I barely run out of spawns.
- Ashenvale, near the area transition to Felwood is a path that leads up into the mountain, through a short tunnel, into a Camp of Terrowulfs (Worgen). They have humanoid loot (if only a little of it) and are skinnable (they yield medium to heavy leather and hides) and have an amazing respawn timer.
- Hinterlands, far to the east, north of the horde Outpost, on the beach spawns a cluster of Turtles (that make funny Hunter pets btw.) that can be skinned for Rugged and Thick Leather, Hides and some Scales or another.
- Hellfire Peninsula, directly north and a tad east of Honor Hold spawn a bunch of lvl 60-62 Hellboars that can be repetetively farmed if you simply go East <-> West south of the big crevice (Orks call it a Road) that leads to the Hellfire instances. Personally I only go there for training purposes because they drop way too much Scraps for my taste.
- Nagrand, north of Garadar, west of the Throne of the Elements, on the shore of the lake, right at a bunch of trees spawn several herds of antelope-like creatures that are non-hostile and respawn quicker than my main can kill them (and skin them and run to the next group ...). These "drop" significantly more leather than scraps.
- Icecrown, this is where it gets tricky. When you enter Icecrown from the Southeast (coming from Dalaran) and arrive at the Argent Vanguard Outpost, spawn a bunch of Nerub's all around the outpost that are skinnable and drop cloth. BUT, and this is extremely important, do not attempt the quest chain in the vanguard outpost though because it phases the territory and removes all the Nerub. If for any reason you already did those quests it still is a semi-good farming spot but you have to go farther north, beyond the ramparts and hunt for the priests and under-kings.
- Zul'Drak, the raptors. Omg, I love the raptors. they are the only spawn (to my knowledge) that drops more than one leather per piece. The downside is, they spawn few and far inbetween but have a decent respawn. I don't think it really pays off when compared to higher populated areas with spawns of a higher density buuuut I just like looting 3 leathers at a time.
- Borean Tundra, in the South are Rhino herds that drop rhino- and chilled meat (both sell decently on my server) and mostly scraps, in the North east at the oil fields (a quest leads you to their hives) are a bunch of Nerubs that drop several bits of scraps per piece. In Coldarra you can skin most of the dragonkin population (they are all over the place, really) and the mana-wyrms that spawn in the crevice' that lead to the Nexus.
- Dragonblight, Icemist Village (next to Azjol Nerub), Nerub again. These spawn here, paired with human cultists that drop a fair amount of cloth (iirc). If you can fly by the time your there get up on those walkways.
Please excuse my poor english, it isn't my native tongue =). Oh, and first post btw. Hope it helps someone along the way.