I have never read a book regarding cryptocurrency or bitcoin. Well, I am not even a fan of reading books and I don't see books about bitcoin being popular here. The nature of bitcoin is digital and we tend to rely more digitally than physical books (even on other cases). Gathering information about bitcoin is much easier online. It takes more time reading the whole book if you're only looking for a certain information. This is only my opinion, and if other want to read books about bitcoin, then go. I'm not stopping you.