Brett Kelly just released Evernote Essentials 4.0. This is the premier book for getting started with Evernote. It's currently on sale for $14.99 (normally $29), so it is a great time to buy. I know what I will be reading tonight. It's a free upgrade for current owners (check your email).
I also did a screencast series on Evernote. If you are looking to go further with Evernote, both products would make a great addition to your library.