Check out this link to get the rollOvers working:
http://cssmarvels.com/archives/14
And erms, I'm from Secondary School and I don't feel personally motivated by this site, which you said was supposed to be made for people like me
I think the place where many of these sites fail is that they do not manage to capture the attention of viewers, mostly because they sound too "educational". Personally, when I see a site that says "Go Green!" or "A Multiracial Society!" and other things like that, I instantly think of propaganda and blatant advertising and just turn off.
I think if you want people to pay attention to your site, you have to make it obvious that this is not some ordinary educational site from the start, include funny facts, not quotes from random books. People want things which capture their imagination, not things that they have heard a thousand times before in school and on television.
If you can do that, I think this site would be a whole lot better.