I actually got "Assassin's Apprentice" for free via Kindle (which is still available: http://www.amazon.com/Assassins-Apprentice-ebook/dp/B000FBFM...). The book was great, and touched off a whirlwind reading of the whole trilogy.

Great series, but the ending was really depressing even though it was pretty clear what would happen to the main character from book one onward.