Israel Guide book is something that I can't and will not try to convince you not to buy. There are many Israel guide books, and I don't know which one is better. The only thing I know that a country like Israel cannot be toured basing on guide books. The complicity in a country like Israel will not find place in the Israel guide book. The diversity in a state like Israel cannot be described in Israel guide book.
Having an Israel guide book with you when you are in Israel, can help you get information about good restaurants, main sites in the country, opening hours of services, nice hotels and even some limited historical information about sites.
But, in order to have more than that, Israel guide book is just not enough. To know a country like Israel you have to really be familiar with its history and it's past. Knowing Israel means: knowing the mentality and culture of the people. If you know the language and the customes of the land it can help.
Therefore the best way to travel Israel is with an Israel tour guides. Tour Israel with guide will give you something that will not find in an Israel guide book. Israel tour guide knows all the things that are lack an Israel guide books. Israel tour guide will be familiar with the history and the past of the country. Israel tour guides will know the mentality and culture of the people. Israeli guide will know the language and the customes of the land. Above all Israel tour guide is someone that lives in Israel, updated, has a point of view and learned in its profession at the University of Israel.
So, before you come to Israel it's good to have an Israel guide book, but don't forget that it will not provide a substituted to a professional Israel tour guide.