Rendering with Mental Ray and 3ds max is a good book. It is based on 3.5 ad max 2008 but you should be all set because it covers the A&D materials. There are the new Pro Materials in Max 2009 with 3.6 but that's straight forward once you understand how to use the A&D materials.
Here is a link to amazon:
http://www.amazon.com/Rendering-ment.../dp/0240808932
See also
http://www.amazon.com/mental-ray-May...3038654&sr=8-1
Other helpful Mentalray sites
Sampling in Mentalray (Understanding sampling in any renderer is important)
http://www.impresszio.hu/szabolcs/Me...aySampling.htm
You don' need a book if you read up on Jeff's site and blog
http://jeffpatton.cgsociety.org/blog/
http://www.jeffpatton.net/