If you're looking for a book about Moodle, our Moodle books database has a wide range of books and manuals for teachers and administrators in various languages, written by members of the Moodle community.
New titles include Moodle 2 para Professores by Portuguese language pack maintainer António Vilela, Moodle 2 for Teaching 7-14 Year Olds by Moodle HQ Documentation fairy Mary Cooch, and Moodle Gradebook by Rebecca Barrington.
Buying a book from the Moodle books database helps support Moodle development, since a percentage of all sales goes to the Moodle Trust.