I cannot name a best book because I learned most things here in the forum. I would assume that you would learn a lot about materials and shaders if you search for BagginsBill's postings and read them - I doubt that you would find better informations in any Poser book at the moment.

A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

Avatar image of me done by Chidori.