Some links that might be of interest...
National Radio Societies
Radio Amateurs of Canada (RAC)
The American Radio Relay League (ARRL)
The Radio Society of Great Britain (RSGB)
DX Clubs
Other DX Related Links
Contest Links
Yankee Clipper Contest Club (YCCC)
Potomac Valley Radio Club (PVRC)
Longwave
Longwave Club of America (LWCA)
Medium Wave
Canada-US AM Station Info Lookup
Shortwave
North America Shortwave Association (NASWA)
Utilities
VHF
Worldwide TV-FM DX Association
Six Meter International Radio Club (SMIRK)