http://www.gearpictures.com/s_steroid_cycles.htm

Post Cycle Therapy

After all steroid cycles men should use Clomid to help restore natural testosterone production in the body. Testosterone boosting supplements such as Tribulus Terrestris are also helpful in raising natural testosterone production. About 1-2 weeks after your last injection you should take 50mg of Clomid each day and 500mg of Tribulus Terrestris twice per day for 3 weeks.
Some people also like to load up on Creatine after a steroid cycle to help maintain their gains and prevent a post cycle crash.