I'll sound like a broken record, but for the technical side of things, Andreas Antonopoulos' Mastering Bitcoin is very good, as well as the upcoming Mastering Ethereum and the Bitcoin and Ethereum documentation. For the non-technical side of things, I like the Sovereign Individual and Seeing Like a State.
You can't really understand why cryptocurrencies came about or where they're going without being familiar with books like the Sovereign Individual and Seeing Like a State. More terms to Google: panarchy, catallaxy, polycentric law, public choice theory, the economic calculation problem, bearer instrument, seignorage. See also my answer here.