Real, paper books, that is.
I just signed on as a review for Blogging for Books. It's a breeze to sign up. I will get to choose a book a book, they'll ship it to me for free, and I write a review. I can't wait to try it out - you all know how much I love to read. If you're interested in doing book reviews, click the link and sign up (no, I'm not getting anything for recruiting - I just love free things).
Nook Deals has a whole post on how to get free books for review. Click on over there for more details on getting free reads.