I'll second the recommendation on "Mindstorms." The book is visionary and just as relevant today as when he wrote it. I teach programming and electronics to kids (just an hour a week) and my teaching is heavily influenced by Mindstorms to this day.
In addition, my own first exposure to computers with with LOGO on an Apple II. Papert changed my life, and the enduring quality of his work will continue to change lives for years to come.
I'm sorry, at the moment I don't have teaching materials in any presentable form. I tried Arduino-based projects, making parts of a 2D game in Swift+SpriteKit, fooling with Minecraft redstone, and worked through Google's blockly games.
Arduino seemed to be click the best, because it involves a lot of working with your hands (both breadboard and soldering) and you can "see" your creation working in a way that you just don't get with pure-software teaching. At least for the ages I was working with (8-10 y/o) blinking a LED held more joy than putting a 2D sprite into a window.
I thought about publishing a more formal project curriculum, but there's a ton of Arduino project books already on the market, so it didn't seem worth it. Instead I just pitch a couple ideas to the kids, see what they want to do, then we spend several sessions building that.
In addition, my own first exposure to computers with with LOGO on an Apple II. Papert changed my life, and the enduring quality of his work will continue to change lives for years to come.