This is not "farming" exactly, but it is a great way to make money in World of Warcraft. This is literally money laying on the ground. And with ancient lichen in the dungons your going to run, you can kill two birds with one stone.

Then, when you are all nice and leveld up you can make sweeps while you wait for BG or Arena to pop. I sweep down south of Shat picking up Fel Weed and Terrorcones. A 20 stack of Terrorcone sells for about 20g on my server, and the felweed procs Mote of Life which is always nice.

If you have time for serious gathering, I go to Shadow Moon Valley. I fly into the Altar of Sha'tar and start gathering Terror Vine. It is usually empty in Shadow Moon Valley, esp. in the back corner.