hesakeeper also makes an excellent suggestion on getting a pedometer!
One of the ways I've been able to lose the 40lbs I have so far is that I got a fitbit. It tracks how many steps I take in a day, how many flights of stairs and how many calories I burn. That along with tracking my calories lets me clearly see what my intake and output is. 1 lb is approximately 3500 calories, so if I'm eating 500 fewer calories than I burn in a day that theoretically means I'm on track to lose 1lb a week.
Before the fitbit I was probably only doing 3,000-5,000 steps in a day, now my goal is 10,000 steps every day (which is what a healthy adult should be doing) and I average 8,000-12,000 steps a day.