Very good, easy to read, clear introduction to interpreting charts. I read this book with some of my own stock charts in hand and found the majority of the discussion in this book applied. I acted on it the next day, dumping my 'poor' stocks, per the chart, and it has literally saved me thousands of dollars.
Get a handle on your investing and buy this book. It is not a complete resource for you investing knowlede, but it is a good place to start...