The Site is fantastic! Since one of my speializations is brain-based education, I found this an extremely usable Web resource, with just dozens and dozens of great links and activities!
Beyond this under the "free-stuff" link is a link called "Brain Pop for Educators". Wonderful things await the teacher that will utilize these resources.
Very easy to navigate and to use. I found that all apsects of the technical navigating to be designed appropriatedly and extremely efficient for students and teachers alike!