Okay, first off, this series IS sold as "intermediate/young adult fantasy" (seeing as I've been doing some writing in this field--Elevator to the End of the World--I better know what's out there.) However, these three books: 1) The Golden Compass, 2) The Subtle Knife, 3) The Amber Spyglass, have anything but a children's plot. The first book is good. The second is okay (get's you to the third). The third book, though, (so far--half way through) fantastic. This book, the Amber Spyglass, won the Whitebread Book of the Year in England (The best book in all of England spanning all genres, children and adult alike.) The scope of these books are as epic as Tolkien.
These books are very much a precursor to Harry Potter, with an even more amazing plot. Pullman has some serious hutzpah. If you're at all religous (as scifi/fantasy types tend to be less religious than most, though not always--covering my butt) stay a way from these. A number of Christian groups shun Harry Potter. If they had a whiff of this book, they'd be raising some serious "hell".
Anyway, if you got kids of the right age, or like reading children's fantasy (Harry Potter, Wizard of Oz, Narnia, etc.) then this series should not be missed. Besides the Golden Compass has a loveable, viscious, armored, bear, and all the inhabitants have "daemons", and their's an Aeronaut from Texas, and an evil golden monkey!