120 blank, college-ruled pages waiting for you to structure your workouts for maximum gain. Some use it to plan their workouts. Some use it after their workouts to record the routine that they just did. Basic info consists of the date, body weight, and type of training for that session. You can expand it to include checkmarks when you finish each exercise and remarks as to how your body reacted to the exercise. It's also good to record meals, sleep, general health, etc, as those factors play a huge role in the results that you achieve.
Happy exercising. Let it loose and you will win!!!