The Linux Documentation Project is working towards developing free, high quality documentation for the Linux operating system. The overall goal of the LDP is to collaborate in all of the issues of Linux documentation.
Linux.com - For the community, by the community, Linux.com is the central source for Linux information, software, documentation, how-tos and answers across the server, desktop/netbook, mobile, and embedded areas.
LinuxQuestions.org offers a free Linux forum where Linux newbies can ask questions and Linux experts can offer advice. Topics include security, installation, networking and much more.