I'd say you have two options. There have been a couple of threads recently about people who have started with nothing and built a bankroll by playing freerolls
then moving to micro stakes etc etc. However, I'd say that would be pretty frustrating (albeit satisfying if it works out). My suggestion would be as follows.
1) Read an article on Bankroll Management.
There is a superb one in a thread on this forum that I started recently about bankroll management. AlienGenius posted a link in a reply to that post. READ THAT FIRST.
2) Start with a very modest bankroll. You know your own financial situation better than us, but I'd say that $50 would give you a decent start.
3) Whatever your favoured game (ring games limit / NL, MTT, S&G or whatever), stick strictly to the limits in the above mentioned article.
If you are not good enough at poker, you will probably loose your BR, or you may be a break-even player. If you are a reasonably solid player, and stick to the rules of the BRM article, you will make yourself a few dollars to suppliment your income. If you are good enough, you could give up your new job in a few months and play poker for a living.
Stick to the rules of BRM
and good luck.
PS I make no apologies for going on and on and on about BRM!