Proffesions

I wanted to link http://www.wow-professions.com/ it's a very good website with guides on how to level each profession. It works pretty well but sometime you have to be flexible and go away from the guide. Some times the mats you need are not on the auction house, in that case go away from the guide and craft the other items instead of the one recommended. To level a profession from 1-450 costs about 4-8k i would say depending on how good deals you get for the mats.
But i would say that for each profession you have you make about 500g-1500g a day without that much time invested.