Please advise

I have a really hard time not doing every workout dvd I have everyday, I know you should always allow a rest day for muscle groups but does that mean you absolutely cannot do any exercise on "rest" day? And what about exercising at morning,afternoon and at night,,,is that overkill? I just have so many workouts that I love and I want to do them all but I do not know how to get the right balance of workouts and adequate recovery and stretching.