I saw an interesting article today at Moodle.org. - http://moodle.org/mod/forum/discuss.php?d=121208
If you're looking for a book about Moodle, please visit our Moodle Books database, which contains a variety of books and manuals, for both teachers and administrators, written by members of the Moodle community.
Recently added titles include the Moodle 1.9 Course Creator Reference Manual by Ray Lawrence and Moodle for Teaching 7-14 Year Olds by Mary Cooch. Both Ray and Mary are Particularly helpful Moodlers in our Using Moodle course.
Please note that when you buy a book from the Moodle Books database, you're helping support Moodle development, as a percentage of all sales goes to the Moodle Trust.
Looks like a good resource for Moodle books and I like the fact that you're donating to the Moodle trust.