Depends on a few things:

1) The board. Watch out for drawing hands. If draws miss by the river and you are oop, try checking to induce bluffs. Is the board paired? If it is and opponent is raising or betting strong, may indicate trips. How big is your top pair? Is it low enough where villain may have an overpair? How strongly is opponent playing this low board?

2) Opponent. Is villain laggy? If so, try getting them to bet into you, rather than you into them. Is villain taggy? Treat these different players differently.

3) Position. The worse the position you are in, the smaller the pots you want to play in, so bet accordingly. Find out asap wether or not you are ahead- ie. check raising flop oop or betting pot when someone leads into you.

There are so many factors to consider, others include stack sizes, table image etc. It's best that you just practice the hell out of your game so that you feel more and more comfortable with your reading abilities.