If you're worried about playing for money, but find the standard of play on the play money tables too bad, then try the freerolls
. The standard of play on them is also very bad, but as the tournament progresses more of the bad players get eliminated, so if you get to the end part of a freeroll, then you'll sometimes have players that know how to fold. Also, if you manage to place high enough, then you'll win money to try out cash games and see how you fare there without risking any non-poker money.
It's still not great for teaching you how to play against decent players, though, but at least in the free/play tournaments, the better players will be more likely to be the ones surviving to the later stages. I'm currently earning a bankroll on the JunglePoker freerolls (their $3000 ones pay 130 places and I'm up to $39 from their freerolls so far), and Prima poker also has big freerolls. Join in with the experiment several of us are going for - seeing what we can build freeroll winnings into... you'll learn about how to play better, bankroll management, etc.
Another suggestion would be that Holdem is significantly a post-flop game - people can fare OK with random cards if they get lucky or if they play the flop very well. Some variants such as Omaha punish players who don't choose which starting hands to play more, so you may want to try those.
Another option would be to start on the 1c/2c tables at a site (e.g. PokerStars
), and see how you fair - the level of play is still really bad, but if you play a nice tight game, and learn when to fold and how to spot when you're beat, then you may well do OK.