The recommend book is ``CODE'' by Charles Petzold (ISBN 978-0-7356-1131-3). Information concerning it may be found here.
This is a book I've casually recommended before for those who seek to understand the fundamentals of automatic computing. The book begins by introducing the concept of codes through Morse code and the importance of two through examinating this. It then continues by explaining the origins of Braille, making certain to highlight the distinctions between different representations for the same concept.
The book continues to then explain electrical circuits with pleasant diagrams, and slowly introduces encoding information through electricity. It later begins introducing the concepts of number bases, Boolean logic, and this symbol manipulation to perform arithmetic.
Being brief, this book moves from abstract codes to electrical diagrams to Boolean logic to abstract circuits to higher constructs such as memory to Turing machines, building a gradual understanding of what an automatic computer is, then moving on to more abstract software topics.
This book can help instill an understanding of automatic computing, from its fundamental principles, and I can recommend it to anyone who wishes to learn of such things. I've not compared this book to freely available courses in the same, as I've not read any of them; I will likely update this review in the case I ever do.