Penguin USA's Teen Imprint is offering the first book in its bestselling Ranger's Apprentice series as an E-book, for free! It's called The Ruins of Gorlan, and it will be available for a full month, until February 15th. I'd definitely encourage you to at least read the first few pages. I read the novel in regular book form, and loved it--it reminded me a bit of the Inheritance series by Christopher Paolini. Check it out:
Ranger's Apprentice: The Ruins of Gorlan
The sixth book in the series is coming out this summer, so if you enjoy what you read, you have plenty of time to catch up with the series (I know that's what I'll be working on as well!).