If your looking to grind the freeroll circuit to start off, I would also suggest carbon, they also have a steps SnG in which you use $250 play money to purchase a ticket for step 1 whereas only first place moves onto step 2 and gets a ticket for the 3rd step, which the winner of the 3rd step wins $1
real money, but those steps are just crazy.
As for real money, pokerstars is your best bet as it has been mentioned, has frequent tourney's running and you can always find a game to play with only a 10% rake.
But if you do decide to play at fulltilt, may I suggest googling "rakeback sites", where you get back a percentage of the rake you pay, but go to the rakeback site before you download any
poker site and use the rakeback site's links to the poker rooms.
Also look here for some reviews of some of the sites.
Poker Sites - Play at the Best Online Poker Sites!