css/html cross-browser compatibility

I have created a site on a Mac ( Adobe Golive v.8 CS2, Mac Mini (PPCG4) running OSX 10.4 Tiger) I've been using Firefox and Safari to view. You know what I'm going to say next: yes, on a PC, especially in IE, the css doesn't work in some places. I have only checked IE6 on XP. The site uses exactly the same three-column css template throughout. Specifically, there are three things that need sorting out: 1. Width of the main vertical navigation menu is a few pixels shorter in IE6 2. Tables in centre column are being pushed down 3. Search box is deeper at foot - should be same as top There may be other work you recommend to get the site cross-browser compatible and I'm open to suggestions. What I need is someone to check the site and correct any css/html to ensure cross-browser compatibility. You will need to check other IE versions (and on Vista) and other browsers. Thanks.