I don't have a website that has it all laid out, but from the pieces I've seen in the Wall Street Journal, New York Times, and elsewhere, it looks something like this:
After the invasion, CENTCOM will be in charge of Iraq. They could pass some responsibility (or a lot of responsibility) on to the UN (if it participates) or coalition partners. If the UN participates, a general given a UN mandate will probably rule, if it is a coalition, Tommy Franks will rule Iraq. Over the course of three or so years (more or less, depending on progress), the nation will be democratized by degrees, starting with local elections, then regional, then parlimentary, and finally they will elect someone to replace Gen. Franks. Occupation forces may stay there after the presidential election to make sure things run smoothly, then they will mostly pull out with some troops remaning behind at new US air and army bases. While they are there, they will work to repair infrastructure, probably auction off rights to Iraqi oil fields (the companies that get rights would be exclusively from coalition partners - at this point it would be ExxonMobil, ChevronTexaco, BP, ConocoPhillips, and Royal Dutch Shell. Lukoil, TotalFinaElf, and others would get a shot if their governments join in), and try and repair the damage Saddam did to the marshes between the Tigris and Euphrates rivers.