This site is mainly for the Linux beginners to study Linux in shortest time !!!
For advance Linux users, you can ignore tutorial articles and just focus on advanced topics!!!

You can follow below guides:

For the Linux beginners

setup env

Firstly you need one Linux environment for your study, the easiest way is to setup one virtual machine. I suggest you to use virtual box and download installed distribution from virtualimages.com.
setup virtualbox Linux OS
When you have Linux OS, you need install VIM and study how to use it. VIM is used when you edit any files.
install VIM
VIM introduction

study cmds

After you have Linux OS, you can start to play all kinds of commands in terminal. You can find examples for common used commands, or check all commands manpages.
cmds common cmds example
cmds manpages

study script

When you are familar with some basic commands, the next step is to study shell, by shell you can complete some complex and repeat tasks. For Linux OS, the popular shell is bash.
bash

study dev tools

If you are developers, git is necessary for you to manage your source code, and gdb also is necessary for you to debug source code.
git tutorial
git cheat-sheet
gdb tutorial

all useful refs

For more reference about environment, commands and shell, you can find many useful resources.
useful links
awesome resources

For the advanced users

custom env

You can do more customization for your environment to improve efficiency.
vim setting
dotfiles
alias
shortcut

more script

You can choose perl or python for more complex tasks.
shell_compare
zsh
perl
python

more tools

more tools to improve efficiency.
find
xargs grep
sed
awk
tmux

advanced topics

advanced topics about linux theory, and custom your Linux.
advanced topics
linux rss
github trend

interview questions

common questions for Linux interview
common

More Help

ask questions

any other questions, you can ask in below forums.
askubuntu
stackexchange
serverfault

Contribute

If you have any great articles and want to share with others, please send me the links, and I will add them in this site.