How much to deposit?
Personally I deposited $325 split between two sites when I first started playing online. Very first night I placed in 2nd in The Ferguson on Fulltilt, adding another $114 on there.
After playing for some time in micro buy-ins and actually cashing for over $250 in priv. freerolls ($97 in one day), I still actually felt I didn't have enough in my poker bankroll to be comfortably playing in the buy-ins I preferred. So,... the question is really relevant to what one's goals are in
online poker. Mine were to find my own particular niche and then to make sure I had the bankroll to support it so that I wasn't playing with scared money. I personally prefer to keep about 50 mtt buy-ins in my account and my buy-in preference is $26 mtts on Fulltilt.
I also have an account where I made the min. deposit, playing mostly freerolls on it, the occassional priv. tourney and some cheapo ring games. That account seemed to soar a bit for awhile but has levelled off at around $200,.. not enough to play the games I'd prefer to be playing so am using it for more of the same (freerolls, etc.).
I personally don't like playing the super micro buy-in mtts online and do much better in larger buy-ins. Playing at a table of mostly loose pass/pass and loose pass/agg. just isn't the kind of tables I like to be on.
Pretty sure it's just a personal preference. My choice originally was to deposit just one time,.. and to deposit enough so that I wouldn't have to ever again (deposit once then manage it). I did end up depositing again because I discovered the roll still just wasn't big enough.
GL!