My sister is a big fan of these series, she kept saying I should give it a try, so in the end I decided to do so.
Will is an orphan in a medieval England-like country where he really wants to be a knight, believing his father was one. Unfortunately, he is too small to make it into the fighting school, but faith has something better in play for Will. He becomes a Ranger's Apprentice. (Not that Will is enthusiast from the start, as Rangers are very mysterious like spies, and no one really knows what they do, and training with Halt isn't all 'pink fluffy unicorns dancing on rainbows' either.
I have to admit I really liked this book. It was almost impossible to put down, it's so action packed. It's not a big book, with about 250 pages, so it's a quick read, but the story is interesting and has a bit of everything: danger, fighting, training with swords, bow and arrow etc, mystery, but also loyalty and friendship. It's aimed at children over 10, i guess, but it's still very nice to read even if you're older. This is the first book in the Ranger's Apprentice-series, that currently stands on 12 books (and I think it's finished now).
Note: I read a Dutch translation of this book