We''ve all been here many times, so I''ll tell you what I''ve learned.
Well, here are some suggestions:
1) Figure out what genre your game actually fits in (RPG, Strat, FPS, Platform, Shooter, etc...)
2) Find companies which have released games of that sort before. For example, Squaresoft has released a lot of RPG''s.
3) Pick some of those and try to find their e-mail, etc... to get in contact with them. Don''t be discouraged if they don''t respond (remember, they probably get a lot of that anyway).
4) Look for start-up groups to connect with. Sometimes they''ll be looking for games and you''re looking for money or something to that effect.
5) Stick around newsgroups and web-forums (like this one). Go everywhere you might expect to find publishers and read a lot and post a lot. You must have a presence.

Stick around here and you''re sure to get more advice!

Good luck!
Charles Galyon