Annals of Arda: Glossary of the names, places, objects and thoughts of Middle-earth.
BobMoCo Middle-Earth Glossary: Glossary of names, places and other terms for The Hobbit, Lord of The Rings, The Silmarillion and Unfinished Tales.
Encyclopedia of Arda: An evolving encyclopedia, complete with illustrations, maps and an interactive chronicle.
From Middle-earth to Mithlond: Dedicated to the life and works of Tolkien.
Galadriel Worshippers' Army: Listings and detailed information for the major female characters.
The Electronic Tolkien Encyclopedia Project:: Scholarly articles submitted by visitors about Middle-earth topics.
The Thain's Book: Descriptions of the people, places and things of Tolkien's Middle-earth in The Hobbit and The Lord of the Rings.
Tolkien Encyclopedia: Interactive Edition: Read and publish entries to this listing.
Tolkien Gateway: A J.R.R. Tolkien encyclopedia.
Tolkien Monster Encyclopedia: Devoted to all the monsters and races belonging to darkness.
Wikipedia: Middle-earth: Article with sections on the continent's geography, peoples, languages and history.