Two samples are available online. The first one is going to be one of the mandatory readings in my upcoming visualization courses at the University of Miami. The second one includes chapter 4, on calculating rations and rates.
The book is a nice companion to the tutorials that Tableau uploaded a while ago. Well, to be honest, the video tutorials are a bit boring for my taste, as they focus mostly on the business analytics side of the program. Ben's book deals with visualization for communication, so if you are a designer or a journalist, this may be a good place to start.
Ben also has a blog, Data Remixed, and he's quite active on Twitter.
Disclaimer: The first link above is an affiliate link to Amazon.com. That means that I get a small amount of money for anything that you buy after clicking on it. I don't get any cash directly from Amazon, though, but gift cards that I use to buy books. The average monthly payment I got last year was $75.
