How to build cross browser web pages?

I think this question is on every web developers mind. With latest browsers coming in the market, browser compatiblity is an important weapon in every web developers arsenal. You will see this question in many discussion forums. I have found some useful links which tells you how to take care while developing web pages.

Very good reference = http://www.aspsnippets.com/post/2009/05/12/Issues-HTML-and-CSS-Browser-Compatibility.aspx

Validate you HTML at: http://validator.w3.org/

Validate you CSS at: http://jigsaw.w3.org/css-validator/