This book is a great place to start if you are new to druidry and are looking for ways to jump in begin a practice. It is well organized and well written and covers (although lightly) just about everything: personal tools, sacred space, celtic deities, tree symbolism, many types of divination, working with the sun and moon, herbal healing, power animals, connecting with ancestors and the druidic year. It also contains a list of further reading and contact information for many different druid orders.
If you are already established on the druid path, you will probably find this book disappointing. It only has very basic information about each subject and may seem too simplified. It is a very how-to book and if you are already established in your practice, you won't need it.
Also, if you are very factual or looking for reconstructionist druidry, the title alone will let you know that this book isn't for you. The term druidess was not used in history and as the title says it is "modern day". Some ideas don't seem to come from any particular tradition and seem rather fluffy.
I recommend it to those that know what druidry is and are looking for ways to begin a practice while they research deeper.