@tomw to be honest, a lot of the non-fiction in the libraries is already crap. There is no peer review in book publishing, and for some reason non-fiction writers tend to be sloppy or excentric.

Also, especially in software engineering you have to do web searches all the time, and most of the ideas gound are crap. It requires domain specific knowledge and senior wisdom to weed the valuable parts out... And a working recommendation system...