Although I'm not sure exactly what you wish to block, there are no programs that will "block incoming emails if they are not from people in my
address book". However, I think it can be done from within Outlook Express.

To cut a long story short, I'd recommend you have a look at this 'how too' for setting up O/E from Black Viper. He's been around a long time and highly respected: http://www.blackviper.com/Articles/OS/Email/filter1.htm
He also has many other articles on setting up [tweaking] all Operating Systems, including Vista.

For a free Anti-Virus that has an email scanner [most AV's don't]:
Comodo antiVirus http://antivirus.comodo.com/download.html
It won't stop junk mail, but it will stop any Virus. Don't use their Firewall though as it's a bit technical, just download the Anti-virus scanner. The Comodo anti-Virus works well with the free Sunbelt Personal Firewall [by AGV].