The header is nice and well-made.
The other stuffs are just simple though I think you can improve it.
Try to visit some other school web sites and see some of their features. This will help your website look more of a school website.
__________________
Watch out my Please login or register to view this content. Registration is FREE , Please login or register to view this content. Registration is FREE and Please login or register to view this content. Registration is FREE Game
About Please login or register to view this content. Registration is FREE
This looks pretty good, especially for a high school website, which as you are probably aware, usually suck quite badly.
I only have a couple suggestions. I think you have one/two too many different font sizes on the home page. I would consider bringing down the header just a bit so we can see the shadow on the top as well as the footer. Also, the header sub text is not positioned correctly in my default browser, firefox 2. You can use http://browsershots.org to see how your site renders in 40+ different browsers.