Not too long ago, somebody posted an excellnt explanation of what each of the items pictured controlled..I think it was in another post ( perhaps about car paints) but don't know the post or who did it...Thought I saved the link but I ofthen think I did something...It really was an great insight to the controls..

Thanks for any help...
Richard

It is complicated but they all effect the properties of reflected light upon a selected material.  I think I am saying that right.  The one with sliders you can change the values and watch the preview to see how it is changing the material.  The ones with the buttons, I'll let someone else tackle.  I don't know a simple way to explain them.

at the top are colors for various channels:

Diffuse colors the diffusion channel
Ambient colors the ambience channel
Specular colors the brightest part of the specularity channel
Specular halo colors the less bright part of the specularity channel
Transparent and Volume i'm never 100% sure.. i keep mixing them up... one colors light as it moves through the object, the other colors light as it leaves the object (and thus can add color to the shadow of a transparent object)

Diffusion channel:

• This is the color the surface gets once light hits it

Ambience channel:

• This is the color the surface gets regardless if any light hits it

Specularity channel:

• This channel simulates highlights on shiny surfaces, in the real world these are just bright reflections, but the effect often gets simulated with specularity because it is less calculation intensive then the physically accurate methods of (blurry+hdri) reflections.

Metalicity channel:

• This channel adds color to reflective surfaces, the stronger the metalicity the more intensely the metalicity's color gets applied to the reflections. 

Bump height:

• This channel creates bump effect on your texture

Transparency:

• This channel determines how transparent your texture is

Reflection:

• This channel determines how reflective your texture is.

Refraction:

• This channel determines the angle at which light 'breaks' once passing from air into the objects surface

Not Recent.
From a thread from the DTE challenge back in 2000. Links to lot's of tutorials but only one still works. Here's Walter Vandijck's excellent one.
http://users.telenet.be/walter.vandijck/DTEtutorial1.htm

Heres another big one, 14 chapters.
http://homepage.mac.com/hilofoz/Brycehtm/Brycetut.html

http://www.virtual-lands-3d.com/mixing-textures.html

Thank you all..All are very helpful...

3eighty If you want all the control functions etc., I would suggest buying Susan Kitchens Real World Bryce 4 book, it was made when 4 came out but it still applies to all the newest versions as well, that book will tell you everything you ever want to know about Bryce, you can get it on amazon.com and its about 1,000 pages long and weighs about 6 pounds LOL!

Thank you Clay!