I am in the middle of Goodbye, Things by Fumio Sasaki.
So far it is an excellent book on minimalism. It is part memoir, part case studies (with photos!), part instructional manual, and part philosophy.
Fumio is an Apple nut -- so he talks about how he used his iPhone to simplify his life. He also uses Steve Jobs as an example of a minimalist hero. While I disagree with him on these points, I can see where he is coming from.
Other than that, there is a great deal of wisdom about the minimalism process and minimalist reasoning in his book. I am only half-way through, but I'd say confidently that the book is worth a read.