I fall on the opposite side to most of you on this one. At first, I think you need a dictator. One guy/gal to make decisions and get things done...Assign jobs, pass down punishment and dole out rewards. This is quick and efficient. Obviously, this guy needs to be completely altruistic. Dictatorships are a very clean and effective form of government when you have a good one who puts his people first. The historical problem is they always pass the reign down to their offspring who tend to be self-centered disasters.
Later, hopefully a brief time, I think you move to a representative type system or at least have a council.
Would you be acceptable to being judged and punished by a leader? Say you fell asleep on watch but nothing happened, would you take a public spanking or a day in stocks?