It took all of us a long time of reading and playing to figure them all out. Once you understand, it will be like a whole new world. Here are some resources.
http://docs.chaosgroup.com/display/VRAY2SKETCHUP/V-Ray+2.0+for+SketchUp+Help
http://francescolegrenzi.com/blog/static.php?page=vray_guide_eng