[quote name='wubb']Don't unpublished authors typically have to write the book and then send it around to see if anyone will publish it? But I don't really know.[/QUOTE]
you can submit to publishers, but the best thing to do is get an agent, or know someone on the inside.
also, if you have an "idea" for a book, you're further away, though you can hire ghost writers to hash out your ideas, a la most all "autobiographies"
best thing is to research the publishers out there, find the niche publisher (or sub publisher, like Pantheon for Graphic Novels, which resides under Random house) and make the push.
it's easy to get a book published - it's hard to make money off of it unless you find the right agent/publisher.