http://linoxide.com/guide/linux-command-shelf.html
Creating Links
File System and Partition Management How to monitor and manage disks
Yum Cheat sheet
https://www.digitalocean.com/community/tutorials/how-to-edit-the-sudoers-file-on-ubuntu-and-centos great link for instructions and samples
Process Checking
Networking Commands
File Manipulation
File System Manipulation
User Creation
Bash Shortcuts
Dealing with RAM
Other