I really enjoyed the Ranger's Apprentice series as a light read, even as an older teenager. The books are very easy to pick up and Flanagan's style draws you into the story.
I gave this book five stars because it has probably the best battle-scene (it takes up nearly half of the book) I have ever found in fiction. Modern authors and movie-makers rarely understand medieval warfare. They are used to modern weapons like machine guns and artillery, so they use archers and catapults like automatic rifles and cannons. The superhero complex encourages them to follow the exploits of a single hero who can plough through a battalion single-handedly (think the Jedi knights).
Flanagan doesn't fall for any of that nonsense. His battle is interesting, clever, realistic and above all, plausible. The strategies the commanders use make sense, the tactics the warriors use are realistic, and oveall, I finished the book feeling like "that could have really happened". I reread this book just for that. But Flanagan doesn't get caught up in "getting it right"- he stil remembers to keep it personal. You aren't some bird flying over the battle watching it like a an all-knowing god; you watch the events unfold through the eyes of his beloved characters, especially Will, Horace and Halt.