How about some books on Lighting:

 

Practical Guide to Stage Lighting, Second Edition [Paperback]
Steven Louis Shelley (Author)
http://www.amazon.com/Practical-Guide-Stage-Lighting-Second/dp/0240811410/ref=sr_1_1?s=books&ie=UTF8&qid=1312408174&sr=1-1
Light Fantastic: The Art and Design of Stage Lighting [Hardcover]
Max Keller (Author)
http://www.amazon.com/Light-Fantastic-Design-Stage-Lighting/dp/3791343718/ref=sr_1_2?s=books&ie=UTF8&qid=1312408174&sr=1-2

Yeah they're for real theatrical lighting but the concepts will translate to Poser or any other 3D Scene.