I'm a fan of books like this that carry subtitles like - 'Musical adventures off the beaten track' - but my shelves are relatively bare. I have 'Dust and Grooves' / 'Galactic Ramble' / 'Enjoy the Experience' but these smaller, lesser known ones are enthusiastic 'Oh my God you need to hear this' types of reading too:
'The Best Music You Never Heard' (prefaced with 'Lost Classics - Hidden Gems - Amazing Stories')
'Lost in the Grooves: Scram's Capricious Guide To the Music You Missed'
Anyone know of others like this? Feel free to extend the brief to fanzine -World ... I've got a fair few of the breathlessly enthusiastic Paul Major mailing lists too.