Well, good
bankroll managment (BRM) dictates, that you will be limited no matter where you go. I would recommend a site that has low buy-in tournies ($1 or less). Unfortunately, you will be frustrated by the caliber of play (lots of donk at low buy-ins because "it's only a dollar" mentality). However, you must endure this will building the BR to a point that allows your slow climb up the buy-in ladder.
I would also make sure that it is a site that has good
freerolls, so you can help to raise your BR thru freerolls.
FTP and PS have rather weak freerolls, but many cheat buy-ins.
bodog has great freerolls, but not as many low buy-ins. CarbonPoker is in the middle on both aspects. DoylesRoom has limited freerolls and mid-number of cheap buy-ins. Those are the only sites i play on currently.
All-in-all, i would recommend Bodog or Carbon. Just keep in mind that poor players exist everywhere, and you must endure. Play tight-and -aggressive, becuase you have limited room for
bluffing with a small BR. Good luck