Hi everyone great suggestions, but I wanted to point out that sometimes switching to another browser might make some web pages unusable not everyone follows the w3c standards.
My bank's online service won't work on anything but ie 5.5 + . I like Mozilla and Netscape myself. Rumor has it MS is going to add a popup blocker to the next version of IE.

Also I have had fun cleaning up the Blaster worm on plenty of computers running dial-up, worms don't care what speed your Internet connection is just that they can get to the right open port to exploit what flaw its after. I suggest a firewall program as a bare minimum on the computer if you use it to connect to the Internet. I also suggest a firewall program as well as a hardware based firewall like a router if you are a broadband user.
Most consumer routers don't allow outside connections in from the Internet as default. Most commercial routers do not have access rules setup to block connections from the Internet in by default.

Hope that helps in addtion to the other good suggestions.