Shading benchmarks?

I have been on and off of blender for a few years now. The one thing that keeps throwing me off the horse is all the trial and error for getting my models to truly reflect light like wood, metal, clay, and so on. I have a good concept of wrapping textures, but with all the numbers and sliders shading is still overwhelming.

Are there any tutorials out there that show all the numbers and slider positions for each material? It doesn’t need to be perfect, just a benchmark to start at.

An example would be.

Wood: Raymirror: 1.23
Hardness: 2.34
Etc.
Clay: Raymirror: Etc.

Just have a look there, download which interests you and study the settings…

Wow! Thanks a lot.