Focus on exercises that hit your entire core (including abs, hips, lower back, and butt). Planks (elbow, full, side, hop outs) always work great they engage your entire core. Vups force your abs and hips to work as one making it a killer ab workout. Got a stability ball (or even a basket ball) try doing jacknifes they workout your abs, hips, and lower back check it out at ab-workouts-guide.com/stability-ball. Also see stir-the-pot, believe me it'll hit the spot. Leg lifts (figure 8s), reverse crunches, and bicycle crunches will help too. Get some good cardio in... Its the best fat burner and eat healthy (good carbs, good fats, veggies, and proteins). Combine the workouts from above with good cardio and healthy eating and you'll be well on your way to chiseled Jesus abs...lol. Good luck and God Bless!
If you've got a pot-belly then you could burn off the fat with cycling and running and use ab work to tone the area. Be careful though - I know some people who work very hard exercising then wonder why they aren't loosing weight; it's usually because they're eating like pigs when they aren't exercising! Diet AND exercise need to go together. Go for healthier foods and ensure you burn more calories in exercise then you consume through eating. Easy peasy! I guess you could even say "it's a peice of cake!"
As for abs workouts there are a few on my profile you can check out. Good luck!