Never having children myself I don't have any experience with this but my was suffering with the same area. She started exercising to get back to her pre-pregnancy weight, put the "pooch" was still there, smaller, but still there. It turned out what was left was just overly stretchy skin. It's not surprising considering she is tiny women that gave birth to two, ten-pound children....
Try to go to a gym and get an instructer there who can help you reach your goal.
I will try to describe this as best as possible. U can even try this; lay down as if u are getting ready to do push up. Lift yourself up off the floor with your toes and your elbows. You will feel the pressure in the stomach when you do this. As a beginner do this for a few secounds, then lay back down on your stomach. Hope I describe this good for you.
1. lay down
2. lift legs up (ankles touching and legs straight) until 90 degrees perpendicular to your body
3. bring legs down until 6 inches from the floor
^^ works your lower abs and really works too.