Below are some very useful text books that are a great reference (in no particular order):

• High-Speed Digital Design: A Handbook of Black Magic, Howard Johnson
• Microwave Engineering, David Pozar
• Introduction to Electromagnetic Compatibility, Clayton Paul
• High Frequency Measurements and Noise in Electronic Circuits, Doug Smith
• National Electric Code, NFPA

Below are some useful links for your reference (grouped in alphabetical order):
IEEE EMC Society
Laser Institute of America (LIA)
National Association for Radio and Telecommunications Engineers (NARTE)
OSHA Nationally Recognized Testing Laboratories (NRTLs)

W Michael King: EMC Consulting & Training
Lichtig EMC Consulting, LLC
Doug Smith Consultants High Frequency Measurements Site