I think there is literally no time to read every book written for IT. Every topic you need in IT, there is IT book for it. And of course when new version of some software came up, through few months there is book about it, which is usefull. If you are not a robot you can not process every IT subject or read every IT book, there are so many things these days since man invent computer machine. Lots of these books are crap and in them you must really try to find information that you need, but some of them are just great and deal with specific problems.