Below is a list of Electrical related industry groups that provide free technical information on their websites.
For Electrical articles on archtoolbox.com, visit the Electrical page.
Illuminating Engineering Society (IES)
The IES is a professional organization for lighting engineers and designers. Many manufacturers are also members. The IES has an Education Section on their website that provides some very helpful free documents to help designers and homeowners understand lighting.
Institute of Electrical and Electronics Engineers (IEEE)
The IEEE is a large professional association for electrical engineers. The IEEE website has a number of standards publications and other continuing education resources. Most of the site requires an account and much of the standards publications require payment.
National Electrical Manufacturers Association (NEMA)
NEMA is the main US organization for manufacturers of electrical components, electrical gear, and medical imaging devices. They provide many important standards that help keep the public safe when using electrical devices. The NEMA website has a lot of helpful technical information. Of particular help to architects is their section on Life Safety Systems guides and manuals, which will help designers when working with fire alarm systems.