1. The site is a little wide - not really a big deal, but I would recommend you take the red column edges and make them more narrow. Perhaps 1/4 the width they are now.
2. The left "Navigation Menu" column looks wider than it needs to be. If you made it only as wide as your widest link (currently "Server Specifications") you could make the middle content area that much wider (see #3 blow)
3. The content area (center column) is pretty narrow. You may want to look into making more room there, especially because of other pages that have potentially a lot more content.
4. User Login Field. I would use a white background instead of the grey -- the grey matches the background so it doesn't really stand out. I think it looks odd that it matches the background - just my opinion, but even if not white, just something else.
5. The Header. It's very large, both in height and file size (520kb). I would shrink them (the two guys) to half their height (as well as the banner) and look at compressing that a bit - you can get away with lowering the quality value a bit without a noticable visual difference.
Not bad at all over all - I think with a little bit more work, it could turn out very well. Good luck with it!