If a publisher wants your book, you'll receive a contract. The publisher is hoping, a little bit, that you won't read it.
Catherine has seen contracts that strip the authors of all rights to the work, that deny or do not mention advance payment for the author, or that don't require the publishers to publish the book reasonably soon (usually within 18 months). All contracts are negotiable, but publishers count on writers being too dazzled or timid to ask for what's fair. I can tell you what's negotiable and fair, what's typical, and whether you should consult a lawyer.