You should know that the size associated with creatine is largely due to the intermuscular water retention that is a result of the extra levels of creatine. Thats why people cut with it, creatine mono doesn't bloat in a puffy way, it will make your muscles look more full.
Long explanation short, its called cell voluminization, basically increases the size of the cells, which is good.
When you've finsihed a "cycle" of creatine and your creatine levels return to normal you will lose the water weight you gained with it.
The best way to gain mass naturally is through diet. When your bulking, at least 500 extra calories a day to your base metabolic needs. You need to limit your fat intake though. For calorie sake, every gram of protein and carb is 4 calories and every gram of fat is 9.
As usual eat six times a day in small equivilant meals save for breakfast and post workout. Breakfast you can have clean source of quick digesting carbs and a few more than any other meal. Postworkout you need quick digesting carbs as well along with your protein.
Fruit juice, pure fruit juice, thats the best source of quick digesting carbs. | 
