Wikimedia
Wikipedia: Freeware
Encyclopedia article that defines and explains freeware. It lists a number of kinds of freeware as well, and each has a link to additional information.
Other
Anti Spyware Coalition
This site contains industry and educational accepted spyware definitions and best practices, and includes a document listing and newsroom.
Other
Yahoo!: Security Center Protect Your Pc
This site contains tips for protecting computers against spyware.
Federal Trade Commission
On Guard Online: Malware
This site contains practical tips for dealing with spyware malware including clues indicating that malware is present on a computer.
Other
Spyware Warrior
This site includes anti-spyware comparisons, spyware forums and other anti-spyware resources.
Other
Spyware Guide: Spyware, Greynets, Privacy, Botnets, Rootkits, Security
This site contains a listing of a variety of spyware, adware and greynet applications and their behaviors.