A good quick workout would be to start with this:
10 jumping-jacks
10 wide push ups
10 regular crunches
then do
10 jumping jacks where you cross your feet in the middle
10 diamond pushups
10 "carry-the-ball" sit ups
then do
10 front-to-back jumping jacks
10 military push ups
10 "jane fondas" where you do a sit up with your legs crossed in the air
Then increase those numbers as you get better. Thats a small part of the workout I do 2-3 times a week in addition to my lifting.

Hope this helps!