Enzokoh, if you are looking for information, there is alot more information out there on the internet if you Google. There are also alot of sample pictures on flickr for you to pixelpeep how each lens performs. Simply go flickr and search the name of the lens you are interested in. Some lens got their own dedicated groups on flickr.
Only if you want a glossy coffee table book to read casually should you buy such books. Even so, I prefer to save money for photography books with pictures, instead of technical details about lens. but that is just me.