No reason to start playing poker with $200, the odds are you will lose it anyway, so its better to start with a low amount and play at the micro limit.

Sign up with UB and play the penny poker, either Limit or No Limit, if you double your bankroll (Your original investment) move up to the next level and repeat.

This way you can build experiance playing with real money and it won't cost you lots of $$.

Also if you havnt already, you should buy Theory of Poker, its in the links section. The book will pay for itself trust me.

If you have already played on poker sites before and are looking to play in the limits Fnord suggested then he's right save up, but I would suggest $300.