About 90% of Creatine stores in your muscles. It hard to explain how it works, but basically it works as an energizer to help you workout harder & longer. It enters the bloodstream and helps your muscles contract while working out, therefore aiding in muscle mass altogether. Creatine micronized is better absorbed than the Mono.
If you want to bulk up, I suggest getting the powder form and putting it in with a whey protein drink before working out.
Protein, protein, protein.