777, the open book is good for all sorts of things that would take me a long time to explain...that being said, the open book is very important. It tells you where to get out, when to get out, when to stay in the trade, it tells you where the stock might find resistance or support, it tells your entry point, it tells you when to get into a trade, it just tells you a whole lot... but it does not give you the complete picture so you have to use it along with a bunch of other tools to make entry/exit decision...e.g. charts, size, volume, prints... Tell us if you have the open book and we could give you some more tips.
Hope that helps.