There were many types of gung fu (kung fu) taught in Shaolin Temples, these include (but are not limited to): Crane, Tiger, Snake, Northern Praying Mantis, Dragon, White Eyebrow, Wing Chun and Southern Praying Mantis.
Each of the systems taught have sub-systems, i.e.: Shaolin White Crane, Black Crane, Tibetan White Crane and Fukien Shaolin White Crane. There are many styles and, therefore, texts on shaolin gung fu. Which text you buy depends on what you want it for. If you want a basic history and description of each of the shaolin styles, I recommend you look at "The Shaolin Grandmasters' Text'.
If you seek a text which will teach you how to use shaolin gung fu for combat, I highly recommend that you reconsider. As has been the response to many other people who have asked if martial arts can by learnt using a book, martial texts are a good supplement to training in martial arts, but they are not a substitute for good hand-on training with a qualified instructor. It is dangerous to try and use a method learnt in a book in real life self-defence situations. If you are not looking to teach yourself using a book, then disregard this paragraph, I just thought that it should be said if your intention is to teach yourself. Good luck.