OP, your suggestion is excellent, but...
It would take a fairly large book to do this topic justice. The topics you'd need to explain are quite technical, and there's a lot of them. My experience is that the vast majority of people do not want to take the time and effort to be safe and secure with digital technology, its easier for them to be a button pusher and treat it all as magic. Here's just a few of the topics you'd need to cover.
Basic digital communications theory. What digital data is, how its measured (bits, bytes, etc), and how it gets moved around and stored.
Basic theory of how a modern computing device works (be it a laptop, cell phone, or desktop computer). Emphasis on how these devices can be used against you.
How the internet works, covering TCP/IP, DNS, and how ISP's route traffic. Heavy emphasis on how network owners can monitor you.
VPN's, theory and practice. Going into depth on what they can and can't do for you in terms of privacy
Encryption ciphers - the basics on how they work, and what they can and can't do
Wireless networks and ham radio (Wifi, Cellular, and general RF security topics)
Web Sites, Web Browsers, how they interact, and how you can be tracked (cookies, HTTPS, etc).
NSA's mass surveillance - History of, Snowden's leaks, and what they can do for sure, what they might be able to do, and what they probably can't do
Data Mining - how small bits of information from different sources can be combined to get a detailed picture of you and your activities online.
Social Media - the incredible dangers of it from a privacy point of view.
Email, how it works, how to do it securely
SMS, a gold mine for the Telco's and Feds to use against you.
I'm sure there's a LOT more that I'm over looking.