20 seconds of work, 10 seconds of rest. Repeat for 8 rounds. Stick with the same exercise all 8 rounds. Then rest 90 seconds and move to the next exercise. If you don't have one, there are plenty of great free Tabata Timer apps that will run the clock for you.
*If you have any equipment, dumbbells, medballs, jump rope, etc, feel free to sub in exercises like overhead press for pushups, slamball for squats, or jump rope for burpees. Get creative!