Your trepidation is actually healthy, wombat. If you read through some of the other threads on this site, the first question we often ask the user is whether they've scanned for viruses and spyware. It's an all too common problem, and it happens mostly to those who don't know enough to protect themselves.
There are three things you must have on your system if you plan on being a member of the online community (and emails count in this regard).
1. Antivirus software. You have my recommendation on that.
2. A firewall.
Sygate seems to be the popular choice for this. A firewall detects unauthorized attempts by others to access your system.
3. An anti-spyware program.
Microsoft AntiSpyware is what you want in this category, and will reduce the ability of spammers and online marketers to watch what you're doing while on-line, and target you for spam and unwanted advertisements.
With all of these programs, updates are made available on a regular basis, often weekly, which equip you to ward off the latest strains. Updating is easy even for inexperienced users, and can be performed manually or set to happen automatically at regular intervals.
Follow these rules and you should have little to fear.
