There are many good (and some not so good) resources that cover self-publishing. Some of these are in the form of books, others as podcasts, and more as blog posts, all from industry insiders.
By far the best one I’ve seen is the book APE: Author, Publisher, Entrepreneur-How to Publish a Book by Guy Kawasaki and Shawn Welch. As the APE acronym implies, the book contains three parts. The middle section, P for Publisher, covers self-publishing, giving a thorough explanation of all aspects.
While the coverage stops short of being comprehensive—an all-inclusive manual would be both unwieldy and immediately out-of-date—it offers the best self-publishing resource available. Guy and Shawn share detailed information on the options available to self-publishers, based on research that would be too time-consuming for most people to amass.
APE is an essential guide for the beginner and intermediate level of self-publishers. Even the experienced self-publisher is sure to pick up some new ideas and pointers. Though I wouldn’t advise anyone to skip the author section, for those with a publication-ready book, the publisher section may be the place to start.