I usually stick to making my containing divs (the outermost div) 750 because I like to fit in 800x600. It is probably OK to do 1024, but unless your Web site has multiple columns and banners, and advertisements, and most importantly, content, that is not needed.
When I view the page in firefox it is not in the center of the screen. It looks to be about 50-100px off the left side of the page leaving a large gap on the right.
About the white-space. Yes, sort of. I mean you have a lot of space around that one paragraph. Above and below mostly. I do think you could make your font a bit smaller, remove some of the padding, and make the overall width of the layout smaller. Maybe even 600px wide. I don't think Web sites have to be huge, nor logos for that matter. Your menu is also pretty large even with my 1280x1024 resolution.
Your design is also very image based. You could accomplish the same thing with some simple XHTML and CSS with a nice logo, and repeating menu background.