It's not simplistic at all. It's easy to understand, but it goes fairly in depth as to the internals of computing.

It has a very incremental approach. It starts with Morse code, Braille, numbering systems, moves on to logic gates, Boolean logic until it reaches microprocessors, character encoding, operating systems and finally some notes on high-level languages.

It's renowned as a classic anywhere you go. Very entertaining, too. It has a casual writing style.