Unless you're satisfied with being published by a small press, you must romance literary agents until one falls in love with your ms.
Here are some links on the subject.
Nope, no idea why the last link looks like a tome. There is LOTS of info at these links. It should keep you busy for days.
And some very good news for debut authors: (must read this) http://www.alanrinzler.com/blog/2009/12/17/publishers-desperately-seeking-insanely-great-debut-novelists/