Perfect example of a user-friendly site, Wikipedia provides a great navigation experience, along with a comprehensive help section and a FAQ file. A keyword-based and powerful engine returns effective results, with search windows on any page.
Dealing with text-only content, a keyword search option is exactly what users need. Search windows are positioned essentially on any page, always providing effective results
Wikipedia provides access only to pages in html/text format, with printable options and upload of images and other media files
A very comprehensive help section and a FAQ file are provided, while general navigation is simple and successful
As a global project, Wikipedia is a perfect example of a user-friendly and accessibility-driven collection of sites