These websites should provide you with the basic (up to advance) command line skills, as well as teach you some neat command line tricks.
1. LinuxCommand.org
LinuxCommand.org is a Linux education and advocacy site devoted to helping users of Linux operating systems.
Visit LinuxCommand.org.
2. Linux Command Directory
Linux Command Directory is a directory of 687 Linux commands with descriptions.
Visit Linux Command Directory.
3. The Linux Cookbook
The Linux Cookbook presents “recipes” for preparing or accomplishing a particular, specific thing.
Visit The Linux Cookbook.



