A company is not interested in buy a complete design document, in fact a completed design including the technical detail is far more useful in house. If you want to start your own company get to know the people in your computer science department who have similar interests. Form a team with them and develop the game together. Once it finished you can self publish it till you find a major publish. A publisher is far more likely to listen to you if you have finished product to sell and not just an idea written on paper.

I think you need to gather a little core group first to pull all the things together - start with getting 1 graphics-guy and 1 programmer to work with you so that your team knows what is realistic and what is not. If I understood correctly you know the story, continue refining it into a functional specification with the help of your artist(s). Your programmer should start working with techical specification and solving technology-issues.

Once you have a functional design document that solves even the the smallest details and such you might start looking to build a company. Trust me, otherwise all this sense of wonder around managing things and dreaming just takes over and you get nothing done. First things first.

If you''re really interested in starting to *design* games, follow these steps:

1. Learn how one makes a game. Don''t overlook this, because the more you know about what everyone else on the team does, the more productively you can design your game. You can jump into this process of learning by creating your own game with one of the easy-to-use programs like Games Factory/MMF or Game Maker(I especially recommend Game Maker since you can download it for free and do plenty with it). With more time and ambition you can study full programming languages instead of the scripts those programs use, which seperate you from your hardware. But learning programming is a tough venture if your heart isn''t in it.

2. Study other games to see what they did well/not so well. Games of any age(today, 10 years, 20 years ago, board games...) are worthwhile to look at.

3. Write down your basic ideas and visualize what your team would do to produce the game(the artists would make models/sprites to represent x characters and objects, and the programmers would simulate the combat by processing y variables in manner z...), keeping in mind budget and time. Sometimes you can innovate by coming up with a cheaper, more abstract way to represent an aspect of the game.

4. Round up the team as stated in above posts. Start with a small team and then add people as you develop, because the early stages of development tend to include different/fewer people from the ending ones(planning and prototyping vs. polish and debugging).

If you don''t think you can really design the game all by yourself, you can still start up a company, but you''ll then have to either hire someone to design the game or take time with the rest of the team to collaborate on a design - if nobody makes a design and the staff doesn''t stick to it, the development may flounder and go directionless. Your role during development will then be a combination of "producer" and "marketer." Besides finding the initial capital, you''ll make sure things are going on the right track and plan out how to promote and sell your product.