I got one that fits in my camera bag: "Digital Photography Pocket Guide, second edition" by O'Reilly Digital Studio. 114 pages. This is the best pocket guide I have found. Very handy to take out, find what you need quickly, make your camera settings and shoot.
The local Barnes and Nobel bookseller had about 50 digicam books to choose from.
Broken down into three sections:
1. What is it? Explains the front, back, top, bottom and sides of the camera.
2. What does it do? Explains dials, buttons and menus.
3. How do I? Explains shooting tips.
4. Appendix:
a. Exposure compensation reference guide.
b. Flash mode settings.
c. White Balance settings.
d. Camera modes and explanations.
e. Metering modes and explanations.
f. Exposure starting points for sunset and astophotography.
g. Megapixel to print size reference.
h. Number of shots=capacity for cards.
i. Color temperature chart in Kelvin.