From Dos/Windows to Linux Howto
When I tried to switch from Windows to Linux for the first time I felt left alone. The web was not what it is now. Tutorials and help documents were scarce or non-existent, and one had to have a friend who could help out, or do it the trial and error way to get Linux installed and configured. Linux is becoming more user friendly now, and lots of tutorials and help sites pop up that help beginners and guide them through the basic installation and configuration process.
One of these websites that I can recommend is Linux online. They've written an extensive tutorial that explains many Linux concepts and tries to answer all questions that you may have prior to making the switch to Linux or installing Linux as a dual-boot operating system on your computer.
Update: The site itself appears to be no longer available. An alternative is the learning section at Linux.com that is offering tutorials, answers, documentation and new user guides.
Te new user guide section aims to explain Linux concepts to new users of the operating system. If you never came into contact with Linux before, this is a good section to start. It contains Linux migration guides, for instance how to keep Windows games or to access Windows data from Linux, installation tips, or choosing the right Linux distribution to replace Windows on a computer system.
The answers section works much like Yahoo Answers. You find and can post questions here, and read answers from other users. The service is not highly frequented, and sites like Yahoo Answers or a Linux community forum may be more helpful if you have open questions about Linux.
Linux documentation finally links to free Linux books that help new and advanced users make the most out of the operating system, and Linux man pages.