Creatine isn't a hormone or a stimulant. It won't cause the dramatic strength increases an oral steroid would but creatine is a very effective 'staple supplement' that is very inexpensive and you can take year round with no side effects.
What creatine supplementation does is super saturates your body's creatine phosphate ATP energy system. This increases endurance and strength in explosive movements like weight lifting and sprinting.
Supplemental creatine is nothing more then the amino acids glycine, arginine, and methionine synthesized together. It is not a hormone and does not require a PCT (post cycle therapy).
I personally use the creatine formula Ancient Strength from n2bm.com. I take one serving (5g) 30 minutes before each workout.