The Basics .... but not easy:

30 sec intervals bursts no break in between:
(try for 15 + reps in 30 sec on all movements)

1. squats
2. push ups
3. sit-ups
4. alt lunges
5. tricep dips off chair
7x through = 17.5 minute workout!

STRETCHING for 10 minutes
and you are done in under a half hour