Here's my Top 10 list of steps you should take to protect your information and your computing resources from the bad boys and girls of cyberspace.
-Back up everything! You are not invulnerable. Catastrophic data loss can happen to you -- one worm or Trojan is all it takes.
-Choose passwords that are reasonably hard to guess -- don't just append a few numbers to a no-brainer. Always change default passwords.
-Use an antivirus product like AVG or Norton, and set it to update daily.
-Update your OS religiously and be vigilant in applying all security patches released by the software manufacturer.
-Avoid hacker-bait apps like Internet Explorer and disable automatic scripting on your e-mail client.
-Use encryption software like PGP (pretty good privacy) when sending sensitive e-mail. You can also use it to protect your entire hard drive.
-Install a spyware detection app -- or even several. Programs that can be set to run frequently, like SpyCop, are ideal.
-Use a personal firewall. Configure it to prevent other computers, networks and sites from connecting to you, and specify which programs are allowed to connect to the net automatically.
-Disable any system services you're not using, especially apps that could give others remote access to your computer (like Remote Desktop, RealVNC and NetBIOS).
-Secure your wireless networks. At home, enable WPA (Wi-Fi protected access) with a password of at least 20 characters. Configure your laptop to connect in Infrastructure mode only, and don't add networks unless they use WPA.