One thing I would like to note is that pedometers are fine but you might get annoyed with a cheap/free one. I had a pedometer that I believe I got free and it kept resetting itself and seemed pretty inaccurate. I then got an Omron pedometer and it worked beautifully. I'd recommend that if you want a pedometer that you invest in one although you can try a free one to see how well it serves you.
You can't out-exercise poor eating habits.