PAC World Magazine - Up to date information on protection application and implementation of IEC 61850.
IEC 61850 Blog - Most comrehensive IEC 61850 Blog with useful links to documentation.
IEC 61850 TISSUE Database - Lodge questions and problems as well as follow resolution of issues with implementation of IEC 61850.
UCA International Users Group - Wide range of information on technology deployment in power systems.
IEEE Power & Energy Society - Specific information on power system areas of interest.
CIGRE Study Committee B5 - Protection & Automation Information specific to the B5 Study Committee on Protection & Automation. Includes Smart Grid, Metering.