This is a loose biography of St. Gerard, and largely concerned with his spiritual qualities and his path to becoming a saint, including a recount of the canonization in exacting detail.
Saint Gerard is a "saint among saints" - my words, not necessarily anyone else's. The holiness of this particular man is well known and detailed very well in this book. So much so, perhaps, that I would hesitate to put this book in the hands of certain Catholics or non-Catholics for fear of potential scandal - even though the author himself says that no such thing could happen. Some acts and behaviors attributed to this man are difficult to understand without a thorough understanding of Church doctrine, traditional acts of penance, and demonology.
So I wouldn't call it a book that anyone could read. Additionally, the intercessions and miracles attributed to St. Gerard are so numerous as to become somewhat tedious in their enumeration throughout the pages of this book. These are the only reasons I would rate this based on my enjoyment of it. It is an excellent picture of a mortal man who almost seemed to already have one foot in heaven.