I found Jillian Michaels workouts to be really great post baby. I do one of the 7-day shred workouts (about 40 minutes) for a workout. If you are out of shape, you can work your way up from the 30 day shred which are more like 25min.
Otherwise I would split your workouts between weights and cardio and do the cardio in intervals (you can also do lightweight reps while on an elliptical or treadmill). It wouldn't hurt to hire a personal trainer for a session or two to develop a workout plan for you.
Also, depending on how recently post-partum you are, I found this ab circuit to be really great:
http://www.bodybuilding.com/fun/post-natal-ab-training-fit-mommy-core-circuit.html
It's much easier than I'm used to, but they put this caveat up front. By doing it, though, I think I'm already in much better core shape than I was several months post-partum with my first and I'm only 7w with #2.