I've experimented with this. In the begining, creatine will help add mass, big time, only if youre creatine intake is low. Hmmm....whazzat? You say you don't take creatine and are just starting out? Think again. There is 1 gm of creating in 1 lb of
red meat. If you're a regular red meat eater, chances are that creatine will not have that much of an affect on you. If you're a veggi, then heck you'll gain 5 lbs in 2 weeks.
So you want the optimum dosage? 5gms a day. More if you're over 200 lbs, less if you're less than 200 lbs. You can take more if it makes you feel better, but you'll be wasting your money. Forget about loading. Thats a way to sell more creatine.
When to take it? After a workout, when your muscles are pleading for it.