Diet is probably the most important. Lots of small meals during the day. And at the start, drink more water.
Lots of situps help the midsection. Knees pointing left, then up than right, than middle than left than... However many you want. Upping your heart rate is also key to burn fat. Too high once a day makes you just more hungry after that. Go for 3 medium speed walks a day if you can to maintain a bit higher average heart rate.