Stomach Muscles
There are a lot of different exercises you can do to strengthen your stomach muscles. However a lot of them are harder than they need to be. Your abs muscles are one of the easiest muscle groups to exercise if you know what you are doing. A lot of exercises that focus on other muscles still give your abs a good workout. However that is also a good reason to take be careful.
If you strain your abdominal muscles too much you will be sore for days and it will prevent you from doing other things. You can exercise your abdominal muscles 5 or 6 days a week if you want but take it easy. I would spend an hour focused on my legs or arms but not on my abs. Try to spread your ab exercises out doing a little at a time.
Visceral Fat
Some of the fat in your abdominal area may be below your muscles. It is called visceral fat. Since it is hard it can be mistaken for muscle but it is bad for your health. For example it can lead to heart attacks. Other fat is just below the skin and covers your muscles.
Since most of the exercises that focus on your abs are not very good for getting rid of fat I would recommend you focus on getting rid of the fat first or while you are working on strengthening your abs muscles.
http://www.muscleandfitness.com/workouts/abs-exercises/six-week-power-abs-routine
