This document will summarize the level of support for web standards and maturing technologies in popular web browsers. It covers the Internet Explorer, Firefox, and Opera web browsers, with focus on the HTML, CSS, DOM, and ECMAScript technologies.

http://www.webdevout.net/browser_support.php

Download the web developer toolbar extention here..
and read the complete tutorial

PIE has a good list of IE BUGS

Firefox is a browser built for speed and security, and getting rave reviews from the likes of PC World, PC Magazine, and USA Today — even Microsoft's security program manager runs Firefox! This free and fast little browser can block unwanted popups, and keep your desktop clutter-free with tabbed browsing. It's definitely more secure than Internet Explorer,

 read full @ http://browsehappy.com/