Digital Disorientation

I have been a mid-fi guy my entire life.  My current system consists of PSB Image T6 floorstanders, NAD C375 BEE int amp, NAD C546BEE CDP, and "nice" speaker cables/ICs.  I have also accumulated ~400 CDs over the last 25 years.  I have been looking for a book/site that explains the digital world from file formats to DACs,music streamers/players, and setting up a proper system - basically the basics on digital music.  I would eventually like to migrate in that direction but need the information in order to make the right decisions.  Any input would be appreciated.  Thanks in advance.