The Photographer's Eye: Composition and Design for Better Digital Photos by Michael Freeman. Guide for creating compelling composition in photographs.
The Negative by Ansel Adams. The second book in the classic series by photographer Ansel Adams.
The Camera by Ansel Adams. The first in a classic series by Ansel Adams.
Professional Photoshop: The Classic Guide to Color Correction by Dan Margulis. Methods for enhancing your images using Photoshop. Best for those with experience using Photoshop. Recommended on bestphotographybooks.com
The Digital Photography Book by Scott Kelby. A guide for beginners who want to shoot photos like the professionals. Learn which settings to use, buttons to push, and when to do it. Recommended on bestphotographybooks.com.
Photojojo! Insanely Great Photo Projects and DIY Ideas by Amit Gupta and Kelly Jensen. Ideas for what to do with great photos after you've taken them!
The Elements of Photography by Angela Faris-Belt. Discusses the four elements of photography and provides practical exercises. Recommended on bestphotographybooks.com.
The Art of Photography: An Approach to Personal Expression by Bruce Barnbaum. Great for beginners and professionals, with many illustrations and graphics.
Lighting: Photo Workshop, by Chris Bucher. Learn how to use lighting to create successful photos. Part of a well-reviewed "Photo Workshop" series.
Understanding Exposure by Bryan Peterson. Manual for achieving successful exposures. Recommended on "50 must-read photography books" on Pixiq.com