It's really important to understand that this book is one of a large movement centred around using the Tarot from a counselling/Jungian point of view, rather than as a magical/divination tool. The card definitions in the books are unrelentingly positive and based entirely on the querant's psychological state and perceptions.
Don't get me wrong -- it's good as a book of counselling tools, and it doesn't pretend at any point to be anything different to what it is. Most of the spreads are presented as techniques for guiding the patient through the session and the card definitions all have suggestions for what the counsellor and patient can do together as activities to develop on what they have seen in the cards.
If you want to use the Thoth Tarot for magical or proper divinatory purposes this book really won't be much use. Some of the definitions develop interestingly on the uniquely Crowleyan perspective presented by the deck, but in general it really blunts the card definitions down, limits them by applying them only to the inner psychological state and drowns them under bland syrupy homilies to stop people topping themselves when they draw The Tower.