Welcome to the world of web design, now you know why we (as designers / developers / programmers ) hate our lives.
Internet Explorer 5.0, 5.5, 6.0, 7.0, 8.0, and 9.0 ALL have different Browser Model engines, and will ALL view websites differently. You must learn to effectively write your code for almost all of those.
Chrome and Safari use the same BME.
FireFox is stand alone - almost always the same in all their browsers, 4.0 (their latest beta) changes a few structurals with support for CSS3.
Netscape is a pain in the ***. I don't even support them, as individuals using netscape have other options - such as Chrome, FireFox and Safari, which are more widely supported.
For the 'layout' you can see 'Zen Layout' ( http://groups.drupal.org/node/10724 ).
Zen is picture perfect for structuring objects for almost all browsers.
You can download 'IE Tester' to see how it looks in all IE versions
( http://www.my-debugbar.com/wiki/IETester/HomePage )
Beyond that, you'll need to learn how to code specifically for certain browsers, and exclude others.
As far as I know, you're only capable of targeting IE browsers, or excluding them individually.
FireFox specific CSS is -moz-.
Good luck.