I think i'm a little confused on your question. Are you doing this site in flash or html/css?
if it's css, check out this site, it shows you the code, etc...
this is how to hook up an external css file to your site.
CSS How to
this is how to create a css rollover link.
CSS Pseudo-classes
if you are doing it in flash, i would check out this website..I believe it was NotJustGraphics that sent me that way...and it's an awesome flash resource...
kirupa.com - Flash and ActionScript Tutorials