I suspect they plan to push additional updates as they release more cables. That means a remote connection (secured with a secret: SSH key or similar) and something like rsync to update the files. There is no standard and reliable way to do that in Windows (as far as I know).

I just looked around the Ubuntu repositories for nostalgia's sake and found Fraqtive (http://fraqtive.mimec.org/). It looks pretty slick, uses multiple cores and SSE instructions to get you there faster, Win/Mac/Linux.

The last 3 minutes of exploring would have taken weeks on my Apple II.

I'm a big fan of CS Unplugged. It's generally aimed at a slightly older age range, I think, but you can probably adapt some of their demos quite easily.

There's a reasonable chance that there's somebody at your local university that would be interested in working with some interested high school students. Finding that person could be the tricky part: I'd suggest going to the relevant department's web site and see if you can find somebody who does outreach/recruiting/admissions.