I know I mention this almost every time someone asks the question, but once more: *no one* knew more about exposure than Ansel Adams, and his books contain more information on that subject than any others I have read.
"The Camera" goes into the settings, lenses, and such. One of the chapters explains why a lens does not affect perspective, a topic that is usually misunderstood. "The Negative" shows how (and why) to get the exposure you want, which is rarely the exposure the camera chooses. No, this is not light reading but if you want to learn why not learn from the best?
If you are getting into home printing "The Print" is extremely valuable. These are the photography books I refer to more than any other, and they are still relevant to digital.