From your perspective, your pot equity is the likelihood of you winning the hand by the showdown. You should constantly be evaluating what you feel your equity is at each stage in the hand... Preflop, Flop, Turn and compare it to the pot equity you feel you feel your opponents have and to how much money is in the pot. I recommend downloading a free software called Pokerstove that let's you analyze equity.
Pokerstove
I know I didnt explain it that well, but I hope this helps along with the other responses.