A couple of the best statistically-bent Baseball Primer posters have a book coming, and I'd be amazed it if wasn't full of great material. I've preordered it, and if the sabermetric side of baseball interests you at all, these guys are pretty danged astute.
Payment for this product placement: Two popsicle sticks, and I get to keep this old birdcage. Still got it. (Actually, this is an unsolicited plug. If you've ever read a TangoTiger or MGL post on Primer, you'll know what to expect from the book, and that assumed quality is why I'm plugging it....)