I don't know how new it is, cos I got it in paperback, but this is the best book I've ever read on Dylan's songs, his songwriting, and his motivations in writing the songs. I recommend it to those who are interested in this subject. Everything in it rings absolutely true to me.

It's by Paul Williams and it's called "Bob Dylan - Performing Artist", also subtitled "The Early Years". It covers Dylan's songs and performances during 1961-73.