A new book on PD, ideas and descriptions of pieces from the 1st International Pd~Convention in Graz in fall 2004:

bang | book

Grab it, it's free.  There is also a DVD which goes with the book.  It's available in the music library or for download as well.

There are also lots of lecture materials, tutorials, patches, etc, from the event found here:

http://puredata.info/community/projects/convention04/lectures

...lots of interesting stuff, including a fellow running a small radio station with PD!!  One in particular worth reading, which is at a beginning level in its intention is this one by Hans-Christoph Steiner, called "Building Your Own Instrument using PD".  He is the same guy who maintains the PD-extended builds I have been recommending for download.

Building your own instrument using Pd