However you decide, that they agree with. That's really it. There are some standards/boiler-plate options, but deals can be structured a lot of different ways. The key, important piece is getting it all in writing, with signatures. Graphic design, packaging, that sort of thing is usually a "work for hire," out-of-pocket expense, either by the hour or per project. Contributing artists, songwriters, producers, ghost writers, etc., etc., can be paid upfront, given points, or a mixture of both; it depends on what you offer and what they accept (negotiation). The important part is a signed agreement, and getting releases from any performers, musicians, etc., for their tracks, so you have no legal worries about rleasing the recording(s).
You may want to limit the "point-spread" (amount of people that will be looking for royalties later), because it can become an accounting nightmare for you.
GJ
