If you have useful links to add or good advise regarding the topic feel free to send me a
PM
Common Nasties on the network
WARNING: Viruses on network you should be aware of!
A link to everything regarding viruses etc. including free Antivirus downloads
http://www.virus.gr/english/fullxml/default.asp
Free P2P userfriendly firewall (Not supported. Symantec bought the rights to it)
Sygate Personal Firewall
More info about nasties
Symantec Security Response Center (Ty to Dreamtech)