Code Cleanup

I've been away from the whole website scene for a while, and every time I stop working on websites, I lose valuable information. Anyway, I've started work on my page, but even though my code is nested well enough for my liking, the CSS and XHTML still feel a tad cluttered. Would any of you be able to help me out with my page, and CSS style sheet? The link to my page is http://www.michaelbull.net/home.php. I have some major annoyances with my page as well. One of them being the fact that there is no space underneath my footer like there is with the header in IE (if you're confused with what I mean, check both pages in Firefox and IE and you'll see what I mean). The major problem I have is that I want to put in a horizontal list navbar underneath my banner area, and it's proving to be pretty difficult. Thanks to everyone who helps out.