Illuminating Engineering Society of North America
The IESNA is the recognized technical authority on illumination. The IESNA site provides information on all aspects of good lighting practice, programs, publications, and services.
www.iesna.org

Knowhow Series Guides to Saving Energy
The Northeast Energy Efficiency Partnerships, Inc. developed six guides to saving energy while creating productive and comfortable environments. You can download them from this site:
www.designlights.org/guides.html

The Lighting Research Center
The Lighting Research Center is part of the School of Architecture at Rensselaer Polytechnic Institute. The leading university-based lighting research center, the LRC has an international reputation as an objective source. At this site, you'll find information about lighting technologies, applications, and products.
www.lrc.rpi.edu