It is fairly common for developers and publishers to receive emails from individuals outside the industry asking how they should go about submitting game designs. The short answer to that question is that you just email us a copy or stick it in the post.
Unfortunately the answer is not only simple it is also worthless, because the question is worthless. A far a more useful question is “why would you want to submit your design”. What is it you expect to achieve by doing so?
1. Do you want a job? If so then the correct path would be to apply to to the company by sending a resume, cover letter and portfolio – for useful advise on this check out the Breaking In forums of the IGDA http://www.igda.org/Forums/forumdisplay.php?forumid=44
2. Do you want some feedback on your game idea? If so then posting it in a game development related forum such as http://www.gamedev.net/community/forums/ would get you way more feedback. Developers and Publishers are almost always working their socks off to get their current game(s) finished so don’t really have the time to offer feedback on every design that comes through the post.
3. Do you want to hire the developer to make your game? Many developers are willing to talk to potential clients. If you have the necessary finances in place to fund a game development project (anything from tens of thousands for a small iPhone game up to $30 million+ for a Triple A game) then please feel free to email them more details of the proposed deal. Only if the deal is appealing will they want to see a design doc.
4. Are you hoping to sell your idea (or give it away in the hope that someone will make it)? – in that case I would direct you to this article http://www.obscure.co.uk/frequently-asked-questions/selling-game-design-ideas/ which explains why publishers and developers don’t accept game design submissions. Every developer out there is the same – more ideas than they will ever be able to make. – If you want to get your game made you will need to hire a development studio or make the game yourself (either as a hobby project or by getting a job in the industry, working your way up the ladder and eventually getting to a position where you get to decide what game gets made). More details on how to achieve either of those aims can be found at the web sites I mentioned above.
So, if you have a design doc just looking for a home (but have no industry experience) I hope the above helps you to better decide your next course of action.