Good timing. I started looking for a kind of "Bitcoin for dummies" book for my mom. Even she (60+ yo lady) asked me to put some of her savings into Bitcoin.
One of the "problem" is, I believe, that most books have been written by the bitcoin/blockchain experts and therefore are quite technical. It's like when you want to read something about mental health and pick a book by the Harvard professor.
Exactly like @tunnelrat and @mattclarke said. You don't need to understand how exactly does it work. Another great example would be airplanes. Do you know exactly how is it possible that the huge heavy thing is in the air? You fly anyway and give your life to the hands of the manufacturers and pilots. Because you trust that it works.
There are blog posts, and maybe even some books that cover this. And once you understand it and are interested in learning more, you can dive deep into it.