It may not work for everyone, but I've noticed certain foods I was eating seemed to put on more weight. I lost about 60 lbs in about six months (maybe less) by cutting down on the amount of dairy and pasta I was eating. I also started going for portion control and getting more physical activity. I've got a bit of a caffeine thing (and a carbonated pop thing), so I switched to diet pop -- way less calories!

A friend also recommended http://www.everydayhealth.com to me as a way to track what I was eating and find healthy recipes -- between exercising and being healthy, I've gone from being big all my life to being about 25 lbs overweight at this point. The sad thing? The best thing for me was to actually eat out more. We eat a lot of meals as a family that aren't healthy, so the healthiest thing I could do was to stop eating meals with the family as I was unsuccessful in getting them to change their habits. Although now they're considering it.