One of the most notable things about this album is that, while there were a few false starts, they used the first complete take for each track, which is astounding. I personally think it's the greatest achievement in the history of music.
Unfortunately, it seems like there is a sore lack of good criticism--critical studies of music that attempt to understand the music more than rate it--and this is especially true of popular music (pop, rock, rap, country, electronica, etc.). I can think of one place that's really good for rock history: Only Solitaire (http://starling.rinet.ru/music/index.htm). That guy's opinions are certainly not the last word on that music, but he does do a good job of putting artists and albums in context. For other kinds of music, maybe start with a Wikipedia article and go from there and see what you find.
