I've read a couple of articles relating to creatine. You have to be careful when training whilst using creatine as people have injured themselves or experienced muscle cramps or spasms due to the increase in energy levels allowing them to lift heavier weights than they would normally be able to. This puts huge pressure on the body and thus can potentially cause injury. Although the creatine supplements have no currently recognisable side-effects you have to be careful taking them and to follow the dosage guidelines strictly. As the body naturally produces creatine, prolonged use of the supplement can trick your body into to thinking it no longer needs to produce it by itself and will stop. This has implications so make sure you take the breaks as recommended.
You may also see an increase in muscle mass whilst your taking the creatine. The reason for this is that it helps water retention in the muscles. But what happens once you stop taking the supplement? The muscle no longer retains the water and you start to notice that buffed look that you're probably after begin to fade. One of my friends went through a spate of taking creatine. His energy levels increased but he was disappointed as he didn't really see much difference.
Some foods also contain creatine especially herring, salmon, tuna, and beef so adding these to your diet may help.
I am quite skeptical about creatine, not that it can harm your body as there is no strong evidence to suggest this but rather, it's effectiveness.