I think all of the recommendations so far are very helpful, but if I were starting out again and could buy ONLY one book to guide me throughout my entire photographic experience it would be "An Ansel Adams Guide - Basic Techniques of Photography," by John P. Schaefer. This book summarizes Ansel's great series in one book, presents a host of more current information, addresses color photography and is extremely well written and organized. The Upton book is excellent, but it is formatted more in snippets, whereas Schaefer's book reads more fluidly through topic chapters. If you're more ADD, the Upton book may suit you better.
The recommendation for Bryan Peterson's, "Understanding Exposure" is an excellent one as an ADDITIONAL book. Gaining personal control over manual exposure of film may be the most challenging and frustrating aspect of starting out in film photography. The book does an excellent job of breaking down this particular area. But again, I would only recommend it as a supplement to a broader book, like Schaefer's, as exposure is a single component in the much larger scheme of photography.