The key to getting results, whatever they may be, is to constantly keep your body guessing. You may get great results from one or two workouts but as soon as your body adjusts to the stresses on it, your results will taper. I would get a variety of dvd's to start just to mix things up. Maybe one pure cardio (the IMAX 1 dvd has rhythmic step and Max intensity cardio), a circuit (any of her circuits would be great, most have more than one workout), and some weight training stuff (maybe a total body workout to start, like Muscle Max). Also, you may want to consider getting Cross Train Express. It's a variety of workouts that include cardio segments that end with a weight training segments for one body part. There is also a kickboxing workout included and a pure circuit workout as well. I know a lot of people do a purely CTX rotation sometimes and seem to get good results.
Carolyn