Sites
| The Linux Document Project (TLDP) | TLDP is working on developing good, reliable documentation for the Linux operating system. The overall goal of the LDP is to collaborate in taking care of all of the issues of Linux documentation, ranging from online documentation (man pages, HTML, and so on) to printed manuals covering topics such as installing, using, and running Linux. |
| Linux Journey | Learn the ways of Linux-fu, for free. |
Command-Line
| Explain Shell | write down a command-line to see the help text that matches each argument |
Manuals
| Manual Linux eminentemente práctico from ZonaSiete.ORG | Pequeño pero práctico manual de referencia para usuarios medios de Linux. Su objetivo es plantear la solución a los problemas más frecuentes de la maneramás sencilla posible, de tal forma que el usuario pueda resolver su problema cuanto antes para seguir trabajando. |
Cron
| crontab.guru | The quick and simple editor for cron schedule expressions. |
| Cron Sandbox | This opening screen demonstrates the schedule that results from demo timing values. Enter YOUR crontab timing parameters, and click ‘Run’. You will see a list of the dates and times that your cron job would execute. |
Git
| Using submodules in Git - Tutorial by Vogella | This tutorial explains the usage of submodules with the Git version control system. |