Know anyone that knows anyone that knows anyone in the publishing business? You can always just walk into the company (well, probably not always) and pitch the idea (or by phone/email).
From Zero - I am not sure of the process.... Ok, I write the novel out on my computer... then what? Find someone to produce it into a book for me? And pass the first few books around to publishers? Sell the bookline through my own ads and word of mouth? (may be more $$ for me) ... I simply do not know how the process works.
I have friends who have been published, but it is things like medical journals, political books, etc....