I REALLY like Creatine. If you search the CrossFit Message board you will find some pretty good threads on the topic. Why do I like it? Beyond its performance enhancing characteristics (of which ~25% of the populations are non-responders) Creatine has some interesting properties like decreasing oxidative damage (both from exercise and eschemia/reperfusion injury) and it decreases circulating cortisol levels and may increase growth hormone release if taken before bed. Not bad stuff when you consider it is nearly cheap as dirt!
Regarding dosages I would stick with an inexpensive monohydrate and go anywhere form 5-10g per day. As I mentioned above taking it prior to bed may be good with regards to enhancing growth hormone release. I do not see a need to load or take it with some kind of insulin spikker. When you run out of a bottle maybe wait a week before starting the next one. Buy your Creatine in ½ kilo sizes if possible to ensure freshness as it will hydrolyze if exposed to air for too long.