Not quite as focused as his Performing Artist series, these collected essays on Dylan's art are still highly enjoyable. Anything Williams writes should be required reading for any Dylan fan.
You've got to be into Dylan, into YOUR inner personal interpretations of the songs, and curious about how others are impacted by the works. Wonderful music writing, but not for the casual fan.
Maybe our best Dylan writer (sorry Greil and Clinton)... the short book (included here), "What Happened?" about Dylan's born-again is essential reading.