Predictably Irrational is the fun intro, but a better overview of the subject is Poundstone's Priceless - The Myth of Fair Value (and How to Take Advantage of It). It's a newer book and doesn't focus so much on Ariely. I just took a behavioral economics class last semester and kind of feel like Priceless is giving me a better feel for the field than my actual class did.

I'm actually very interested in this problem space and will be thinking about it in my spare time, so email me if you want to discuss it.