This book reminds me forcefully of Harry Potter, and I suspect it will appeal to the same people: although it is in some sense a sequel to Dark Lord of Derkholm (set in the same world eight years later, with some of the same characters), it is quite different in its focus on a group of students attending a wizarding school. Like Rowling, Jones shows a flair for humor (this book is laugh-out-loud funny), quirky characters and magical mishaps, and seems uncomfortable writing any sort of romance. Of course, Year of the Griffin is also much shorter most Harry Potter installments, covers less time, is set in a fantasy world, focuses on six students rather than one hero, and lacks a Voldemort-style evil. Instead, antagonists appear in the form of mindless academia (a problem for these academically-oriented teens), a few rogue griffins, and the angry parents, assassins, etc., who are bound and determined to stop nearly every one of the six friends from attending wizarding school.
Year of the Griffin is a very enjoyable book, and the six first-year students--as well as several secondary characters--are quite well-developed considering the length of the book. While there are some themes younger kids might not pick up on, this is a very kid-friendly book (more so than Dark Lord), and conflicts are wrapped up in a way that may seem a little too pat for more mature readers. Still, it's good fun, and if you're like me you'll finish this one in less than a day.