4 links
Don Klipstein's Lighting Info
members.misty.com
Information and links on various types of light sources and the technology that makes them work.
Howstuffworks
howstuffworks.com
Article: Are fluorescent bulbs really more efficient than normal light bulbs?
Lighting Facts
lightingfacts.com
Photographs and descriptions of different styles of fixtures and bulbs, as well as cleaning tips, wiring diagrams, and suggestions for how to light a room.