I think that if you took The Chronicles of Narnia, The Neverending Story, and the Lord of the Rings, and found a way to brew them together, Here, There Be Dragons is what you'd end up with. And while I'm not a Tolkien fan, I did enjoy this book. And, delight of delights, I was even surprised a number of times.
I was expecting a light YA/teen fantasy, but what I found was a complicated weaving of various fantasy and mythological elements, written in the style of CS Lewis (The Chronicles of Narnia). I enjoyed them, but I wonder how many of the references to various cultures' myths and Arthurian legend the intended younger audience will miss or not understand through simple inexperience, and how much of a difference that will make to the reading.
Were I offering this book to a young adult/teen reader, which I certainly encourage if you know any who are inclined to like fantasy, I would also seek out companion books to satisfy the interests in mythology and legends this book will likely spark. (This might be easier to do browsing in a bookstore than searching online--everything I found was either for adults or a younger audience.)
Readers/buyers should be aware that this is the first book in a series.