ARRL - American Radio Relay League (National Association for Amateur Radio Website)
FCC. Federal Communcations Commission Universal Licensing System (ULS) - Look up any callsign
Automatic Packet Reporting System (APRS) - Link with standardized frequency list
T-MARC - The Mid-Atlantic Repeater Council. T-MARC Coordinates VHF & UHF repeater ops in DC, MD, DE, No. VA, Part of WV
Christiana ARES - Christiana Hospital ARES Group New Castle County, DE
Netlogger - A nice free program to log Nets via the internet. Includes an "Almost Instant Messaging" built in.