Something I can genuinely recommend to everyone here is to read the works of Alfred Landsburgh, also known as Argentarius.

These have been translated into both English and German by now. Written almost 100 years ago, the author explains the fundamentals of our monetary system in letters to his son, who was in training at the time. In an interesting and entertaining manner, various topics related to money are described, starting from barter and credit, to the money market, central banks, and inflation.

Ever heard of his books?