My kids are in ages 8-12. One big problem is that I must find a way to have them work and explore on their own, but most of the tutorials and documentation that I know is good and up-to-date, is in the English language (and I'm Dutch, as are the kids). At that age they really can't yet read English very well.
Of course the best solution to that problem is to spend some more time and try to find good Dutch HTML tutorials. They should be out there, it's just that my Internet bubble seems to be a bit anglo-centric :) Also if Python was invented by a Dutch guy, there should be some quality Dutch language material written on it, no?
But apart from that, I also wonder if there's some other ways that do not involve reading manuals. While the cards thing seems interesting, I wonder whether the kids would be excited about it, it's not a school, they go there after school and are offered the opportunity to work on all sorts of technical projects with our guidance (there's also an electronics lab where they get to solder resistors and diodes and such to make flashing LEDs etc).
I'm kind of looking at how the more "crafts" like departments have it easier (apart from electronics, there's wood, metal working, clay/pottery and more). There, the teacher can just show how to do something and explain, multiple kids can watch and then try it themselves. With the computers it's like they can't do very much or explore new things without me explaining them one-on-one. Which takes way too much time and also isn't really the best way to facilitate the "exploration" aspect (which is one of our goals).
So I sort of know where the problems are, but I'm kind of stumped on how to fix them. Except for taking the time out to write tutorials (and perhaps some screencasts) myself.
I usually teach algorithms without using a computer as well. I put kids in groups, and give them a shuffled deck of cards. How can we sort it as fast as possible? Can they come up with their own techniques? Then we have little challenges to see which group sorts it the fastest, and they explain their "algorithm" to the others.
It's an intuitive way to introduce many concepts (including parallelism, yay) without using a computer. I think it's critical to show that this elegance in computing transcends the machine.