You should start playing for fun first. Play in some free poker games to get the hang of it and learn the basics. Once you feel you are ready to make some real money, you should compare the different poker rooms out there and choose one that suits your needs best. There are many different rooms out there, but some of the biggest ones are: Fulltilt Poker, Poker Stars, Titan Poker, Absolute Poker, and Titan Poker. All of these rooms offer a good selection of games, big tournaments, and good cashiers. So you really can't go wrong with any of these rooms! If you are looking for a good source to learn some poker strategies, I would recommend you read here.