A classic book by astronomer Carl Sagan about how to distinguish science from pseudoscience. The beginning is really interesting and talks about a man who seems well-read, but his knowledge is completely wrong. Stuff like aliens, UFOs, ghosts, Atlantis, crop circles, other supernatural stuff. The book proceeds to debunk all of these in great detail; I got through about 100 pages before I had enough.
Obviously I don’t believe in these supernatural stuff, and I don’t know of anyone who seriously believes it, maybe because of my background, it felt like preaching to the choir. Maybe it would be more interesting to someone without a scientific background.