[ http://www.1902encyclopedia.com/ ]
An authoritative reference library on every aspect of human knowledge.
[ http://dune.wikia.com ]
A complete guide that anyone can edit, featuring information about the Dune series of books and films.
[ http://www.wikinfo.org/ ]
Created in a similar fashion to Wikipedia. Features user submitted information and reference articles.
World Book Encyclopedia
[ http://www.worldbook.com/ ]
Online encyclopedic. Comes with an atlas, dictionary, both audio and video resources and pictures. Free for a temporary period.