Lvl 1-7 - Newbie Area
Lvl 8-10 - Stonefireld/Maclure Farms: Boars (Goldshire)
Lvl 11-14 - Stone Cairn Lake : Prowlers & Bears (Goldshire)
Lvl 15-23 - Crabs on Longshore (Westfall)

If that doesn't work and you need gold quick, I recommend The MMORPG Exchange WoW Gold. They deliver quickly and are cheap! I usually receive my gold within 20 minutes. They're my secret weapon, I highly recommend them!