I have an extensive arms-related library, and still I'm stumped by your question.
For one thing, you really can't learn shooting from a book, and that goes double for self-defense shooting.
Nevertheless, I can recommend some helpful beginning material.
When I was a kid, my father bought me W.H.B. Smith's Small Arms of the World, which covered the functional operation and disassembly of the military small arms of WW2, rifles, pistols, and machine guns. It was an excellent beginning for my trip through the world of shooting. I believe that this book is still in print, but I would not buy a revised edition, since I believe that the newer versions are not as complete.
Next most useful are the NRA's two Firearms Assembly books. Although they do not discuss functional operation, they present disassembly instructions and "exploded" drawings of just about every rifle, pistol, and shotgun of interest. You can learn quite a lot about functional operation from "exploded" drawings.
Then there's Jeff Cooper's Principles of Self Defense. This book won't teach you shooting, but it will help you learn what can be done, and what can't. Follow that up with any number of books by Massad Ayoob, who discusses not only technique, but also applicable laws.