Well, I'll try.

The "small belly" may be due to more relaxed abdominal muscles.  To
strengthen them, you need to exercise them.  There are a lot of exercises
for improving abdominal muscle tone, and I recommend you start with mild
ones and work up carefully from there.  I have no idea what effect your
surgery will have on your ability, but starting with 50 situps is a real
bad idea for anybody.

This is a scam, and any benefit you get from it will be due to the diet and
exercise recommendations, not the quack sessions with the vibrating pads.

Here's a link to information about controlling your weight:
http://www.nhlbi.nih.gov/health/public/heart/obesity/lose_wt/index.html

Use the BMI calculator to determine what your healthy weight is, and the
Information for Patients to learn how to achieve and maintain it.

If you are only slightly overweight, and have usually been of normal weight,
you can probably reduce and control your weight quite easily.  Exercise
will definitely help, and most North Americans can stand to reduce their
fat intake and especially saturated fat intake substantially.  This will be
good for your health in general.

Some simple suggestions to reduce fat intake:
- avoid fried foods
- remove all skin and visible fat from poultry, and visible fat from other
meat before cooking it.  Eat only lean cuts of meat, and in smaller portions.
- switch to non-fat and low fat dairy products.  Cheese is very high in fat,
so eat smaller portions.
- eat pastries and other goodies only occasionally, as a treat, not daily at
your coffee break.  Even bran muffins can be extremely high in fat.  If you
like something sweet after a meal, eat raw fruit.
- cut back on butter, margarine and mayonnaise.  Ask yourself if it will
really improve the taste of the food you are about to apply it to, considering
that it may more than double the calorie content.  Adding butter or margarine
to vegetables converts a very healthy food into a nutritionally dubious one.

Do all this gradually, and you'll find that you don't feel deprived.  Switch
from whole milk to 2%, then after a while to skim, and pretty soon you'll
find 2% tastes rich and whole milk positively greasy.  Have an unbuttered
bagel or some fruit at coffee break instead of a danish or muffin.  You'll
enjoy things like ice cream and cheesecake more if you eat them seldom
instead of regularly.

Some general suggestions:
- eat carefully in restaurants. There are suggestions in the link above.
- avoid junk food, and refined, sweetened and prepared foods in general.
- eat more vegetables, fruits and whole grains.
- read labels before buying food.  It's always easier to reject something
in the store than at home.  Now that most packaging has nutritional content
as well as ingredients on it, you can ask yourself whether you really want
to eat that, and get a better answer.
- aim for a diet with less than 30% calories from fat.  20% may be better.

You can increase the amount of exercise you get daily in simple ways.  Park
further away.  Get on and off the bus a few stops away from the usual.  Take
the stairs a few floors instead of the elevator.  Take a walk after supper
instead of settling in front of the TV.

One bad habit to avoid is eating while doing something else.  Don't eat and
watch TV or read.  Don't eat because you're bored.  You don't have to clean
your plate.  Don't skip meals, and if you're very hungry, eat something
small and wait 15-20 minutes before starting a full meal.  It takes your
body about that long to reduce the feelings of hunger after you eat something,
and if you're very hungry, you can eat a *lot* in 15-20 minutes.

Be dubious about "passive" methods, like magic machines that lose your
weight for you without effort.  Controlling your weight is basically very
simple, even if it isn't easy for many people.  Consume fewer calories than
you burn up, and your weight will go down.

I hope this helps!