While this is an interesting book about Schubert, it discusses the music much more than the man. You get little feeling for Schubert as a person, and little understanding of his everyday life from this book. On the other hand, Newbould spends a lot of time talking about the music. But his discussions are little more than what you get in liner notes of a CD, and require that you be familiar with the music in question (or have the time to take out all your Schubert CDs and listen to everything he discusses).
I'm a big fan of Schubert's works, and hoped, in this book, to get a better understanding of who he was, why he wrote his music, what he wanted to "say" through his music, but all of that is lacking. The biographical chapters - about half the book - are short, say little more than what music Schubert composed and when, and are fully of "maybes" and "possiblys". It's almost as though this were a bio of Shakespeare (about whom little is known). I don't know if there's a dearth of information about Schubert - Newbould doesn't say so - but reading this book one can get that feeling.
Since there are no other books about Schubert that say much more, this is probably worthwhile, if you can read scores (to grasp the musical examples). But I'd say there's a need for a _real_ bio of Schubert.