I haven't read this book myself, but I've read other books in this series and would recommend them:

http://www.amazon.com/Philosophy-Short-Introduction-Edward-Craig/dp/0192854216/

I like the idea of directing him to the Less Wrong sequences as he would probably benefit more from that. It's available in pdf and other print-suitable forms here so you could print it out and put it in a fancy binder or something:

http://lesswrong.com/lw/37v/sequences_in_alternative_formats/