If you were given a large mass of land, and were told that you were in charge of running it, how would you proceed?

Assuming that this landmass is large enough to accommodate a functioning society, how would you run it? What form of government would you install, if any? Would you create your own? If so, what would it be like?

Also, what would your main laws be? I know that there are many possible laws/rules/regulations/duties, but what would some of your core ones be? How would these be enforced?