[Merck]

I, like probably many people in this forum, am very interested in good sound equipment but I don't own anything other than some IEM's towards the relative low end.  I have no money to budget towards anything related to the reproduction of sound right now but I plan on that changing sometime later in life.  In the meantime, I would like to read about this field in order to prepare myself to make better informed decisions pertaining to the various elements of a sound system.  With that in mind, what are some good books you have read about this?