I personally really hate bright colours like that on a webpage with blue then on top. I don't know why, I just don't.
You could also change the font from Times New Roman to something else even if it's just Arial.
Other than that it's quite good, simple but good.
Oh and just noticed, the white curved lines in the header are very pixelated. You could do with changing them.
Edit:
Another thing... Your Guestbook isn't working.