I don't know if this has been posted before, but I'm gonna have a go anyway. xD
So, in darkshore, close to auberdine, there's a cave. This cave, and it's surroundings has alot of moonkins, which no doubt you can find elsewhere in darkshore. Anyway, these moonkins can earn you a moderate amount of money, considering you're lvl 13, or 14 at this time. So, the reason I picked these moonkins, is because they drop light feather alot. A stack of light feather sells for roughly 2g on my server( last time I checked atleast ), and to me, that's alot of money for such low levels. Sorry I can't be more specific, just can't think of anything else to say. ^^