Each diet book has examples of people who lost weight dramatically. However an important thing to remember is that everybody is different so the weight loss process for you might not be the same as for anybody else no matter what you read in the books, on the Internet or what a weight loss guru says.
Some people might lose weight quickly in the beginning of the program. This usually happens at the expense of retained water and glycogen. Later on the weight loss levels out and decreases to 1-3 pounds per week. This shouldn't discourage you: at this rate you can lose about 100 pounds in one year! Believe me, one year is not a long time - just remember how quickly the time passes from one New Year day to another.
Other people who don't have lots of retained water might not experience a dramatic weight loss in the beginning.
Another thing to consider is your body frame. If you have big bones then the weight you need to lose might be lower than 100 pounds that you decided initially. There are some tables available on the Internet that can help you determine your body frame size. You can measure it using your wrist circumference or the breadth of your elbow.
Based on your height and measurements you can then determine if your frame size is small, medium or large. Then look up at the healthy weight graphs and determine an ideal weight for you. For example, if your body frame size is small your weight should be on the lower range provided for your height.
Respect your body, set realistic weight loss goal and don't be discouraged if you are not losing weight according to a weight loss textbook. Follow your plan and you will achieve your ideal weight.