There are literally tons of books about the Apollo program and the Moon. If you want to waste a rainy afternoon wandering through the Apollo literature head over the forth floor of the Engineering library, they have several shelves of Apollo and other mission literature. Below I have listed my favorite books about Apollo. Most of them have extensive bibliographies if you want to explore further.
This is the book that I used to use as a text for this class. It is a little light on the science, but it does a very good job of covering each lunar mission in detail. Lots of very nice images (many of the same ones I use in class). If you want a good summary of what this class is about, this is a good place to start. Easy to find used and cheap.
My favorite general Apollo book, and probably the best introduction to the Apollo missions. Told mainly from the view point of the people in mission control and the engineers. This book actually makes the engineers' lives sound exciting. Great accounts of Apollo 8 and 13. Newly reissued.
Yes, a graphic novel! It is good enough that I had to include it in this list. A very nice treatment of the story of the early part of the space race (from Sputnik to Apollo 11). As you would expect, there is a lot of simplification and many characters are composites of a bunch of real people, but the spirit is certainly correct. It is also very scientifically sound. I also really like the drawing style.
Written by a scientist heavily involved in the Apollo missions and lunar science in general. Everything you need to know about what Apollo taught us about the Moon. Lots of early history about lunar science, training the Apollo astronauts, choosing landing sites, and the role of scientists during the Apollo missions. The book can get a little technical at times (mostly in the beginning) but generally is it worth the effort. Out of print, but easy to find used online.
Written by the Command Module Pilot of Apollo 11. Easily the best book written by an astronaut. The best place to learn what is was like being an astronaut and going to the Moon. The book is a bit dated now but no other first-hand account of space flight has come close to this one. Newly reissued.
The Moon's reference book. If you need to know something about the Moon, its history, geology, chemistry, or what materials are available to build a colony it is in this book. It can get really technical but if you need to know this is the book to turn to. Used copies are really expensive, but there is a $30 cd-rom version available online.
The ubiquitous yellow bordered magazine found at every used book sale. National Geographic published nice summaries of most of the Apollo missions, all with great pictures.
February 1969 - Pre-Apollo look at the Moon - lots of great Lunar Orbiter images. Also includes a nice fold-out Moon Map. May 1969 - Apollo 8 December 1969 - Apollo 11 - A classic, even has a cool record you can play. July 1971 - Apollo 14 February 1972 - Apollo 15 December 1972 - Apollo 16 September 1973 - Apollo 17