At the bottom left hand corner of this page,
http://www.sfdm.scad.edu/faculty/mkesson/Ca301/
you'll find a number of links to some of the student renderman work completed by students of the Savannah College of Art and Design. I've chosen to list these particular students because they have provided good explanations about the use of Houdini and Prman.
Malcolm Kesson
Prof. Visual Effects
Savannah College of Art and Design
GA
USA