The BAM book is interesting in places if you have an interest in the story around the guy who claimed he wrote Possession and then killed himself because that takes up much of the book.... Otherwise its not that good as she (Judith Fitzgerald) seems more interested in talking about herself or putting down Sarah & Terry McBride rather than talking about Sarah's life... It does however have an excellent selection of old press cutting and pictures of old merchandise in there!
From Lilith to Lilith Fair is a better book but it covers more than just Sarah so I wouldn't recommend it as a bio of her. I do wish Sarah would do her own book like Tori Amos and Jewel did, I think it would be an awesome read!
Plenty is the best book as my friends who I have made the Writers Block Cookies for will tell you!