A collection of books, howtos and documentation on GNU/Linux for offline use
If I am asked which is one of the most important strengths of GNU/Linux, then I would tell you that it is the documentation. That is right! What makes GNU/Linux such a pleasure to use is the excellent documentation that is included with it for each and every tool bundled with it.
Just try learning to use iptables without reading the documentation even once, and you will get the idea. The documentation in Linux is available in a variety of formats - as man pages, info, HTML pages, postscript and in some cases even pdf. These documents are so good that many a times when I have asked questions in the past in various forums and Linux chat rooms, I have often got the now popular RTFM reply which means Read The Fine Manual.
But not many people are aware that you can have additional documentation and even whole books available locally for making your GNU/Linux experience that much richer. Here are a few of them that have come to my notice.