Besides running a good anti-virus and anti-spyware/malware program(s), it’s also good to keep up to date on the latest security vulnerabilities and recommended patches.
I highly recommend the vulnerabilities database at SecurityFocus — http://www.securityfocus.com/vulnerabilities
It’s become even more important to me lately as I’ve helped both clients and customers with hacks to their WordPress or Joomla sites.
I highly recommend BugTraq also — but either subscribe to the daily digest or you might want to archive it to a 3rd party email storage account such as Gmail — because it can easily be a hundred or more emails per day. BugTraq is the oldest security reports and discussion list on the net. Very cool!
-Roger
P.S. Many software packages have their own security announcements email list or RSS feed — you definitely need to subscribe if you’re using their software!!! For example, check out Joomla Security Announcements.