The design looks dated -- like late 90's. Congrats, though, on updating the coding. The next thing you might look into is semantic coding -- using headings and such.
Now that you're taking the CSS plunge, you may want to start using some online resources to help you with your coding. According to the HTML Validator, you've got quite a few errors to fix. Once you get those fixed, look into using the W3C CSS Validator.