1. Use Mozilla Firefox.
2. Be suspicious of all e-mail attachments.
3. Be extremely cautions of links in e-mails, IM messages, and IM profiles. 
4. Think twice before installing software from unknown companies.
5. Use anti-virus software, and keep it up to date.
6. Take advantage of free anti-malware software.
7. Use an e-mail service that scans incoming messages for threats.
8. Consider making the switch to Apple computers.
9. Avoid using add-on toolbars in your web browser.
10. Keep your Firewall on.
11. Be careful of P2P file sharing networks.
12. Use a limited Windows user account for daily activities.
13. Be wary of security warnings that ask to download software while you browse the web.
14. Read all unexpected messages and dialog boxes.
15. Use common sense, and go with your gut.

via ofzenandcomputing