<em>How We Know What Isn't So: Fallibility of Human Reason in Everyday Life</em> by Thomas Gilovich
<em>Why People Believe Weird Things: Pseudoscience, Superstition, and Other Confusions of Our Time</em> by Michael Shermer
Check your local library for these two books, especially How We Know.
And the Kindle version of Gilovich is only $14, and it can be read on any device!
http://www.amazon.com/How-We-Know-What-Isnt-ebook/dp/B001D1SS2M