PREFLOP:
It depends how others are betting. If everyone is limping, then I would raise 4 times the BB. If someone has already raised the pot, I would double their raise (unless it equals less than 4 times the BB, then I would go to 6 times the BB) to further isolate the hand.
FLOP:
Regardless of what flops, I would lead out with a pot sized bet to see if I can take the pot down right there. If the board is showing a lot of overcards and your bet is called, you are probably behind and now you have a choice to make.
TURN:
What I would do here is try for a check raise. Chances are, my betting thus far has at least scared him into believing that his top pair is at least suspect, so he will make a small bet to try and take the pot down. With a check raise you are still showing strength after he bets, and you may be able to take the pot down. If not, you are not having to commit another pot sized bet into the pot and get to see the river for cheaper than anticipated. However, if your opponent makes any more than a half pot sized bet here, you might as well fold and cut your losses.
RIVER:
Once again, if you get called on the turn and haven't hit your set yet, then you are likely beat. I would try and check the pot down.