I am Linux : Being A Ultra Linux User

Linux is an open-source operating system whereas Windows OS is commercial. Linux has access to source code and alters the code as per user need whereas Windows does not have access to the source code. In Linux, the user has access to the source code of the kernel and alters the code according to his need. Currently, more than 300 Linux distributions are actively maintained. There are commercially backed distributions, such as Fedora (Red Hat), openSUSE (SUSE), and Ubuntu (Canonical Ltd.), and entirely community-driven distributions, such as Debian, Slackware, Gentoo, and Arch Linux.

This Book covers All Basic Linux knowledge, Commands, and Free Cheatsheets which is very good for Beginners.