A few recommendations. First, It probably looks fine at 1024 x 768 resolution, but at 800 x 600 about an inch of the paeg is off the right side of the screen requiring scrolling. I try to design my pages to be tabled at a max of 750 pixels, or else use percents for width so they resize. With the latter, some layouts can distort though, so be sure you test your pages at both resolutions.
Secondly, you might want to use a mouseover on your menu buttons. and make them seperate buttons instead of an image map. Image maps are larger images, so they're slower to load, and they prevent you from doing mouseovers and the like. Make identical buttons to the existing ones, but with white text, and have it change to the white version on mouseover. There's tons of mouseover scripts out there, and there's ways to table and use <div> tags with your images properly to still have it layout like your image map currently does. Hope this helps!