There are things to remember about betting if you really want to learn how to bet properly.
As it has been said above, when betting pre-flop, betting 2.5-3xBB plus one for every limper is the norm.
Post flop betting is based on the size of the pot, board texture and if it has hit you at all.
If the board hasn't hit you and you are given the chance to bet at the pot first, then a c-bet(continuation bet) of about 1/3 the pot is good.
If you hit the flop but the board is draw heavy then a 3/4 to a pot sized bet is in order here to give improper odds
for drawing hands to call.
If I'm wrong on this, I'm sure I will be corrected