And, yes, the $600 first deposit bonus is real money. You get $$ added to your bankroll as you play hands, usually over a 60 or 90 period. You can't clear a $900 bonus playing 4NL or 10NL, though. You can get bonuses at different sites as you move up in bankroll. I would not deposit a ton for two reasons. First, it's not risk free for US players. Second, you can learn the game without committing a ton of cash. You can still get your br kickstarted with a bonus, so choose carefully.

On FTR, we call the games with SB/BB $.02/$.04 4NL because a standard 100 BB buy-in is $4. 10NL is blinds of $.05/$.10 and a standard buy-in of $10.