Find the publisher's name on the spine or the copyright page of a book. If you don't have a book use a search engine on the Internet. Locate the publisher's contact information.
Contact the publisher through e-mail or by telephone and explain why you want to buy directly. Most publishers will be happy to speak to a customer, but also reluctant to undercut their distributors.
Ask for remainders or damaged books. Many publishers take returns of books only slightly damaged or leftover from bookstores and sell them at a discount.
Meet publishers at trade shows and book fairs. Book business is often conducted at fairs and conventions like Book Expo America and the Southern Festival of Books. International book fairs are now very popular too. The Frankfurt Book Fair is attended by almost all of the major publishing houses.