Keep everything on your system updated.

Use a Anti-Virus that has "real-time" monitoring.

Use a Firewall.

Learn "safe hex".

Use a more secure browser such as Firefox

Use a more secure e-mail client such as Thunderbird

Use spyware scanners such as Spybot S+D, AdAware, Spyware Blaster and keep them updated.

Use a system monitoring tool such as WinPatrol, Spybot has one included called "TeaTimer".

Use script blockers such as Script Sentry and Script Defender

Don't download just anything you find-investigate first!

Use some type of spam filtering program.

Set your e-mail program to "read in plain text".

Beware of attachments-open only those you are expecting to receive.

Don't forward mail that was forwarded to you.

Use another AV program as a backup for your main AV.

Use a pop-up stopper/ad-blocker.

Make backups of all important files and keep them in a safe place (burn to CD-R).

Use strong passwords-a combination of letters and numbers (use the shift key as well) is best (minimum 15 characters).

If you post on newsgroups-"munge" your address.