I have seen a number of weight loss programs on the Internet that track your exercise, diet and give
You advice on meals and stuff. An example of this is weight watchers. Can anyone tell me what the best one is that they have heard of or used??? Thanks. Does not need to be free

check_out third & fourth link on : wWw.lose-weight-gain.info

Any of those programs should help you, as long as you keep in mind one very important thing:
calories in < calories out = weight loss
calories in > calories out = weight gain
calories in = food
calories out = BMR + exercise
BMR = Basal Metabolic Rate (the amount of calories you need to eat in order to maintain your current weight)
All of this is approximate and subject to fluctuations due to your metabolism, body composition, etc. But in general, this is the main rule. What makes this easy is that usually you want to have a good 500 calorie difference between your In & Out calories. Generally this will mean a net change of 1lb per week (500 x 7 = 3500 = 1lb).
You don't need a paid program if you understand the above information. But, if the program helps you understand the above information in greater detail, or specifically caters to you as an individual and takes into account your current age, weight, height, gender, and your goals, then I say go for it. But if you're the type of individual that just needs to be armed with a little knowledge, then follow the above and just use a free online calorie tracker & database.
http://www.caloriecount.com is a good one. I used it a while back to learn how many calories my typical diet was giving me, how much nutrition I was getting, and also used it to achieve my weight goals.
Good luck