I do not work in finance, but I became curious about such things when the financial crisis hit. I ended up reading (among other things) Understanding Modern Money by the economist Randall Wray and the more populist 7 Deadly Innocent Frauds by the former trader Warren Mosler. Those books were the first time that I glimpsed a coherent view of what "reserves" and related topics are (seriously, almost every traditional media mention of the word "reserves" is a bit confused in some way - this really should be a topic in school curricula).

Since then I've just been piecing more things together by following blogs and tracing their statements back to original papers, including things like the actual text of the Basel regulation agreements and corresponding national laws (of Germany, where I'm from) and central bank publications.