Can someone critique my redesign?

I redesigned the Brown University Bookstore website, because as a student there I've had a lot of trouble navigating it.

I redesigned it (mostly wireframes), in hopes of improving it a bit. I'm definitely not great at this, so improved usability, rather than aesthetics, was my focus.

Here's a link to an explanation of the redesign:

Any critiques or feedback would be greatly appreciated!