Skinning/leather QFollow

Arathi Highlands, Circle of Inner Binding, Level 33-34 Raptors
Alterac Mountains, Chillwind Point, level 32-34 Lions, 30-31 Turtles
Duskwood, SE corner, Nightbane Wolf-men, 27-31
Stranglethorn Vale, Anywhere depending on your level, Tigers, Raptors, Panthers, Gorillas, etc most from 30-42+, generally the further south the harder.
Thousand Needles, The Shimmering Flats, Scorpids 32-34, Turtles 31-35

Theres a few, generally any skinnable mob 30-40 has a good chance of giving heavy leather, closer to 30s give medium as well, clsoer to 40 sometimes gives thick.

After filling 3 bags with nothing but heavy leather (primarily) I can say that Stranglethorn Vale is a heavy leather goldmine. A stack of 10 sells for 15s. So if you have 12 slot bags (like me) and you can fill up 3, that's almost 2 gold a shot (1.8). NOt to mention that close by is the Venture company's meterologist lake where you can sit and grind gobby's for hours on end. The lanterns they drop are 15 silver a shot plus money drops and cloth drops.

There is also the Bloodscalp trolls in close proximity as well, which drop so-so for money, but also give up silk and wool (which sell really well).

I think Stranglethorn Vale was made for those at lvl 35 and up that are saving for their mounts.

Grind Humans or Beasts...up to you.

don't know. I am a hordie so I take the Zepp there. I know it's North of Booty Bay (I laugh every time I say that.)

So it's possible....LOL. I know that it's East of Duskwood, if that helps.