I really like Shannon Hale. I did read this series a bit out of order. It is supposed to go: Goose Girl, Enna Burning, and River Secret. I read River Secret first, but having done that, it didn't take away from my enjoyment of these books.
As is in the style that Hale uses, it's very clean, a little romantic, and has a good deal of adventure. I would certainly let any of my children read it when they are older, and do not hesitate to recommend it to friends.