exersise dailey, (dont over do it) and eat healthy meals, (salads, and baisically what sweetpea03 said)
oh and a good fun sport to do is ice skating. if there is a nice rink near you, go skate around the rink for an hour. it is great exersise and burns a lot of calories (assuming you have strong ankles and properly laced skates)
good luck :D!