I've been running a pretty large mod team for about 2 years.
We all decided that we wish to establish a game development company, and start working on a title for PC. I have begun forging relationships with people that can assist us in accomplishing that goal. Some of these people told me I need to write a feasability study then a buisness plan. I have all the books I need on auctual mmo architecture and game design, now I just need some for the marketing, management and buisness side of things.
Some I enjoyed, generally cover startup info for business/marketing/sales with lots of examples: