Recently I finished reading Greg Milner's book Perfecting Sound Forever, which is a well-researched history of recording.
Starting with Edison's wax cylinders and covering the development of the rival Victrola, the introduction of magnetic tape after World War II, then Philips' compact disc and, finally, discussion of the loudness wars initiated by radio stations that have blighted popular music in recent years.
The explanations of the technology were easy enough for me to understand but the highlights seemed to be the people on the periphery who I'd never heard of before, like Leopold Stokowski and John Diamond. The latter has ignited a long-running debate about the effects of listening to digital recordings and there's an interesting quote from Rupert Neve on this topic on another blog of mine.