If 3500 calories = one lb....then in a week, if you eat 500 calories less a day(7 days x’s 500 calories), then you’ll lose 1 lb a week (even if you don’t do any excercise). Now, with a good fitness program, it will help you feel better, and work off even more weight.
Your goal should be to be healthy of course, and stay within a healthy weight for you.....that varies by every person, body type etc. How you get there depends on how much you can dicipline yourself to staying within a certain calorie count vs what you expend.
The best way to start is to KNOW how much your eating now. So, without making any changes in your diet, track your daily intake for a week (I use http://www.fitday.com) After that week, once you know your average daily calorie intake, continue to track your daily calorie intake, keeping 500 calories off from what your had posted the week earlier. It’s all a matter of calories taken in, vs. calories expended. Excercise will keep your body more fit (and the extra benefit of expending calories too)!!!
Keep up the great workouts....a little every day.....
Take care!