Hi there seacat22
+1 to what PerusJamppa said about having to play looser, however I think there are some important things to understand about that... basically 6max is exactly the same as fullring, only you don't have the first 3 early positions. UTG in 6max = MP in fullring and so for that reason the ranges are relatively wider... but that doesnt mean that you should say "hey, I'm playing 6max - I should loosen up!" - I think that would be a mistake.
The most important thing in 6max is adjusting to the players at the table. In my opinion you wouldn't be making much of a mistake if you just brought your tight fullring game to 6max tables at the beginning. This will keep you out of trouble... I made the mistake of moving to 6max and actively trying to play looser, because that's what I read, but then I found I was getting totally owned. So here are some pointers:
1) Don't adjust too much just because "it's 6max" - just play your normal game and adjust only as much as is necessary given the table conditions and your opponents.
2) When thinking about loosening up you should pay the most attention to the CO and BU to start with - stealing will increase your vpip/pfr in a profitable way. Also, the blinds come around quicker so you need to pick them up more.
3) Set mining is overrated.
4) Post hands!
I hope that helps.
Lewis.