I have three requirements for you if you are setting up a computer in your home.
First, you need a router. This is the small box that would sit between the cable or DSL modem and your computer. With it you can hook up more than one computer to the internet, you can get them to read files from other computers, and maybe connect to a printer or your TiVo. But *most importantly*, it is vital for protection from attacks from the internet. Honestly, if you do not have one, you should go out *today* and get one. Call me if you have questions about this.
Second, you need virus protection. I have used all the majors, but I am fondest of avast! antivirus software. I put it on Kristi's computer, it works great, and it's free to home users! You have to register once a year, but I have never received any kind of spam from them.
Third, you need something against spyware. I want to compare it to a mess you get on the bottom of your shoes when walking in the park. It's not immediately dangerous, but if you're not careful, the walk in the park can ruin your carpet and spyware can ruin your computer. I've seen it happen. The big boys are Ad-Aware and Spybot, but Microsoft just joined the party with their MS Windows AntiSpyware. It's still in Beta, but most everything is today. I've loaded it to compare with the other programs, and so far it hasn't caused me any trouble.
If you do not have these three things on your home computer, get them. If you have any questions, leave a comment. Please.