It’s generally a good idea to start freelancing while you are employed, that is, if you have the option. Some people have no choice but to jump right into freelance work. Others have a steady job and therefore the luxury to start freelancing with more flexibility.
I could write a few points here taken from the article I found at Lifehacker that tells you how to start freelancing without leaving your job, but it’s so darn good that I’ll just send you over there. Click the link.