My Brother Joseph : The Spirit of a Cardinal and the Story of a Friendship, about Joseph Cardinal Bernardin, by Eugene Kennedy. Words do not exist to praise this book highly enough. What a life Cardinal Bernardin led; what a gift he was from G-d.
This Jew learned more from this book about American Roman Catholicism and about love and grace and faith --- as Roman Catholics understand these issues --- than I did in college level comparative religion classes, informal interfaith dialogues and the general knowledge base an attentive Jew learns about Christians just by being a member of a minoritarian faith in America.
Kennedy, a former priest and lifelong friend of Bernardin's, has paid a lovely and loving tribute to a man he truly loved. It's a fairly slender volume, easily readable in a couple of sittings.
It's very much worth the trouble to seek this book out and read it.