Welcome Walter,
I like playing at
Titan on the micro (under a buck blinds) Limit and NLHE. It's a good place for you to start and get a feel for the online game. SnGs and Tournaments are good, but you need to have a decent bankroll to get through the inevitable slumps. Online can an All-in fest since people are playing polker like a video game. Once you start winning, then move up to the bigger dollars.
Most people play
Party Poker because it is loose, lots of traffic 24hrs, fast to cash in and out, plus easy-to-earn Bonuses and monthly Re-load bonuses. I played there all last year until their BlackJack game busted me out.
Iceberg.