The Plan Of Attack: Keep a food diary and exercise every single day. Also, you should weigh yourself at least once a week I do it to see where I am. However, the scale is not a very accurate measurement, but that being said, it's a really good place to start.
There are days when I'm working late, and when I don't have the chance to go for the run, I add an extra 20 minutes on the bike. I've made activity a part of my lifestyle now.