A few suggestions, all of which can be found elsewhere but in this case bear repeating:

1. If it works for you, and I have no financial or personal interest in any vendors, avoid Microsoft products. They are not necessarily less secure than others, but they are the most attractive virus target because of their market share. Macintosh users have escaped all the well-known recent viruses.

2. Get one of the major anti-virus checking products, keep it updated via the vendor's Web site (all of them come with instructions for doing this) and keep it enabled.

3. Do not open attachments from ANYBODY unless you know what they are. When in doubt, confirm with the sender.

4. Read enough of the computing press to stay aware of the major viruses going around.

5. Make regular backups, so you'll be able to recover all your important work and personal files in case you have to totally reformat and re-initialize your hard disk.