One of the first lines of defense we have against the plague of security and
privacy problems that stalk the internet resides within our browsers. This
article is meant to help you to harden your browser against all types of
problems. It features specific suggestion for Firefox, Chrome, Opera and
Internet Explorer.
http://www.techsupportalert.com/content/how-harden-your-browser-against-malware-and-privacy-concerns.htm