Due to the wide variety of support issues, we cover technical support issues on a per case basis. You should send support requests by e-mail to email@example.com or call us by telephone on 0161 366 6600. If you call us, please ask to speak to a support technician.
Here are some very useful support links for documentation:
The Linux Documentation Project (LDP) is a very long-standing project whose aim is to document all aspects of the GNU/Linux operating system and associated applications software.
This site is where you can find the official documentation developed and maintained by the Ubuntu Documentation Project. There is a very good Server Guide for each version of Ubuntu.
Very useful for CentOS users but also general Linux tips. Red Hat provides this site as a library of tips, trouble-shooting advice, and other current information updated daily by Red Hat support technicians.
As part of its efforts to create a high-quality free operating system, the Debian Project is making every effort to provide all of its users with proper documentation in an easily accessible form.