Digital Logic Design: A high-level overview
github.com
github.com
My kids enjoyed this book, similar topic, but fairly playful in how it was put together and an extremely gentle introduction without actually shying away from how things actually work. It's hard to imagine a reader not coming away with a much better understanding of what computing is all about. It starts at gates and works up to actual (machine) code at the end of the book. Very good diagrams throughout.
Despite being from 2000, I don't think it's become outdated. I'd love it if there was a sequel that covered putting things together with a cheap FPGA.
[0] http://www.amazon.com/Code-Language-Computer-Hardware-Softwa...
That's what really pulled back the veil on system architecture for me, at least.
I was in my second or third year of University before I was introduced to anything like this in any meaningful way. A 13 year old me would've loved to have stumbled on a GeoCities page with this.
I always felt very behind in college because I didn't know anything about electricity or programming or radio. Digital logic was refreshing because it was one of the areas that pretty much nobody knew about.