Essays by other people. Like I, Pencil, which is freely available on the internet and I could mention a couple of other really good ones. There are some EXCELLENT writers out there today trying to get the economic message out there that have really, really displayed some creativity. There is an essay that I think might still be on a blog, I'll look, that showed a bunch of kids trading Halloween candy and one kind of candy developed as a "money" and they all traded on the basis of that--very well done! It is in a book on Mises.org called "It's a Jetsons World" which is also outstanding, but like Stossel more of a topical book than a traditional exposition of principles.
I'd suggest for money What Has Government Done to Our Money from http://www.mises.org The same site has a PHENOMENAL 40 minute video called Money, Banking, and the Federal Reserve, and it does cost, but it is only five dollars, and it is extremely well done, very high-interest.
Do consider getting the most recent Stossel free video, and look up the Edgar the Exploiter video on Youtube sometime. They are a lot more high-interest than the Khan videos, which are solid, the ones I've seen, but not exactly exciting. Also, John Stossel has a weekly program on Fox Business, if you get TV. You DO need to preview the topic for the night, as once we wandered in and turned it on to discover an hour long program promoting deregulating prostitution (whatever the merits on economic grounds, I wasn't about to watch that with three teen boys!!!) Also he does periodic specials on Fox News and they are usually terrific.
You're right, there IS a tremendous available online now!