Quote - Poser 7 Revealed by Kelly L. Murdock.
This book is always on My desk!

Correct me if I'm wrong, Noel... I can't speak for or against your book since I don't have a copy, but for the material room I've found that most manuals show you how to hook up a texture map node to the diffuse_color channel and put a picture file in the first channel: that's it. They don't go into the other nodes hardly at all. I would do a search here on Renderosity for just about anything that Bagginsbill has to offer... you will find it is pretty much gold standard: it just works.

However, be prepared to learn a bit of maths (if you're not already proficient at it).

There are heaps of examples of shaders (groups of nodes to produce a specific material) here and on RuntimeDNA. I've started a collection (but then, I'm a packrat... lol)

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks