Extraordinary Popular Delusions and the Madness of Crowds by Charles Mackay is available online at http://www.econlib.org/library/mackay/macExContents.html.

My favorite chapter is The Tulipomania. Well worth the read if you've never looked at it before.

I have a little informal group of Vietnamese that I teach the principles of market investing and trading to. This is the first book I make them read.