There are a couple of things you can do
-hop on treadmill to walk 4-5 miles every day (elliptical is better, easier on joints),
-drink plenty of water, eat lots of salads (careful with dressing), drop sweets and eat fruits instead.
-choose lean meats (steamed or grilled), no salami or cold cuts of fatty cheeses.
--obviously, no junk food. eat popcorn if you need a snack to replace chips etc.
-write down what you eat everyday and look for bad patterns.

Some tricks: when you feel hungry try to drink some water first. Hunger sensation may be triggered by dehydration.

All diet programs revolve around the basic principle: less calories in - more pounds out. Everyone is different so learning your body and eating habits is essential. One booked that I liked about dieting is eat to live by dr fuhrman.

My problem started when I torn my acl. I gained a lot of weight and once I recovered I started to work on my weightloss again. I dropped about 17 lbs in 2 weeks because I was fasting (fruit/veggie juices only) and I kept the weight off for about 3 months until something else messed up my entire life and had no time for sports and was eating junk stuff again.

Good luck!