basically, anytime you create something in maya, it's a node.
open up maya's help files (F1)
and search for "node" and look at "what is/are" node
it'll clearify things (i hope)
anyways, sorry bout the long explanation, if i have some time, I'll take screenshots.
Also ... I've discovered some free shaders to download off of
this site
if might speed up the process...