If you're working/playing/just goofing around in Poser, then you should be hanging around in the Poser forums at Smith Micro. There's a few serious and quite knowledgeable Cycles gurus there, who are always enthusiastic about lending a hand. BagginsBill(?) is the go-to gent for shaders and always includes the math used to derive his material nodes...great fun for the older brain trying to keep in shape!