These book provide additional insights on digital photography and computer image editing. Some pursue advanced topics well beyond the scope of this web site, which is to say they go beyond the casual "quick shot" approach to the subject.

The books recommended here cover basic Photoshop, advanced Photoshop, beginning digital photography, advanced digital photography, nature photography, composition, exposure, and photographing children.

Adobe Photoshop Elements 6: A Visual Introduction to Digital Photography (book with CD) (Paperback)
by Philip Andrews

This book provides a good starting point for those new to digital image editing on a computer. It will get you started with Photoshop. A CD is included.
Adobe Photoshop Elements 6 book cover
Advanced Photoshop Elements 6 for Digital Photographers (Paperback)
by Philip Andrews
Advance PE 6 book cover
The Digital Photography Book (Paperback)
by Scott Kelby

This provides an introduction to the whole world of digital photography.
Digital Photography book cover
The Digital Photography Book, Volume 2 (Paperback)
by Scott Kelby (Author)

Advanced topics include serious portraiture.
Digital Photography vol 2 book cover
The Art of Photographing Nature by Martha Hill (Author), Art Wolfe

This is a book on photographic composition. It includes comments by the photographer and an expert author on the example photographs.  I recommend this book highly. It is all about pointing the camera. Reading the photo critiques I found myself more in sympathy with the photographers viewpoint, but the discussions are always interesting.
The Art of Photographing Nature book cover
John Shaw's Nature Photography Field Guide
by John Shaw.

 This book is a classic. It largely pre-dates digital photography, and some find the references to film a problem. I don't thing so. From the viewpoint of taking pictures, the main difference is that you don't have to load film.
John Shaw's Field Guide book cover
Understanding Exposure: How to Shoot Great Photographs with a Film or Digital Camera (Updated Edition) (Paperback) by Bryan Peterson

Increasing the aperture lowers depth of field, limiting what is in focus. Faster shutter speeds stop action. Careful exposure best preserves highlight and shadow detail. This book covers all the variables in depth. It is way beyond point-and-shoot.
Understanding Exposure book cover
Photographing Children Photo Workshop: Develop Your Digital Photography Talent (Photo Workshop) (Paperback)
by Ginny Felch (Author), Allison Tyler Jones (Contributor)

I know nothing about this subject, but the author does.
Photographing Children book cover