If Villain Raises Postflop, They Probably Can't Fold
One of the many things I've learned listening to Bart Hanson's cash game podcasts is something he calls the "Aggressive Action Theorem." Basically this axiom states that if a villain raises after the flop is dealt, he or she is probably not going to fold later in the hand. This is particularly true at the low and medium stakes tables. At higher limits, the opponents you face are adept at bet/folding and raise/folding, but at the lower limits the villains tend to get "pot committed" and/or married to their hand if they've invested what they consider a lot of money to the pot. Even if they think they're beat, it's hard for these non-experts to fold their hands. This can be either a good or bad thing for you, as you can get somebody to stick around with a worse hand, but it also means that they probably can't be bluffed off a better hand they might have. In any case, just remember that if they raise postflop, they're probably incapable of folding their hand.
All-in for now...