MER is an extensive reference guide for electrical designers, engineers, installers, contractors, facility managers, inspectors, exam candidates, apprentices, electricians, journeymen, architects, and technicians. MER is for people doing residential, industrial, and commercial work.
You may want to also check out their guide to everything you need to know about LED lighting. It describes everything from the benefits of LED lighting, to why you should switch to LED lighting, to how LED lighting works, and finally to how it makes the planet greener. Definitely worth a read!