I really like the Lennard Zinn Books. I have both the cycling primer and road bike maintenance books. The cycling primer is nice, as it talks also a lot abou bike fit, caring for your body, and introduces you to maintenance. The maintenance book is for heavy duty maintenance. He has good diagrams, and with the second book I can tune my bike by myself, although I still bring it in to have major parts changed out (but could probably do more with the book if I chose to spend my time that way).