Through WebAppers, here is a nice article on cross browser compatibility from Anthony Short.
"Cross-browser compatibility is one of the most time consuming tasks for any web designer. We’ve seen many different articles over the net describing common problems and fixes. I’ve collated all the information I could find to create some coding conventions for ensuring that your site will work first time in every browser. There are some things you should consider for Safari and Firefox also, and IE isn’t always the culprit for your CSS woes."