I've been working on this for a little bit and slowly it is growing and growing. I wasn't sure where to put this topic so feel free to move it in the appropriate forum section.
I shall try my best to update this as often as possible.
FORUMS+:
AD&DCampaigns.com
Dragonsfoot
En World
Halaster's Back In Print Project
HotHalflings.com
Knights & Knaves - The True Home of Oldschool OD&D and AD&D
Mortality.Net - A Dungeon Master's Resource
Planet ADnD
The Dragonboard
The Grognard's Tavern
WOTC's Other Worlds Forums
GENERAL SITES & WEBRINGS:
Aaron's RPG Aids & Extras
Citadel Raven
D&D Adventures
DND Epicenter
Darkholme Keep
Dragon's Foot Mapping Links
Leyenda's AD&D Homepage
Lord Piper's Pages - The Golden Enclave
Molly's World
Olik's AD&D Pages
ORCS - Orc Role Playing Community
Realm of the Dragoneers
RPG Gateway
RPG.Net
The Core Hardpoint
The Dungeon Master's Page
The Pathology Guy - Some Generators
TSR Role Playing Game Links
ADVENTURES:
Jeff's BH2 - Skullmountian
RPG Archive - Home Brewed Adventures
NETBOOKS+:
Blue Troll's Netbooks
Defrag's Realms
Cult's Netbooks
FanCC Miscellaneous Netbooks
GBNA - Archives Section
Oak Dragon's AD&D Page
Olik's Archive - NetBooks
Rondak's Portal RPG Resources - Netbooks (Seems links are broken)
The Great Net Book of Net Books for AD&D
The Great Net Spellbook
The Treasure Chest
CORE RULES CD:
Bruce's Treasures - Some Core Rules Downloads
ALTERNITY & DARK MATTER:
AL-QADIM(ZAKHARA):
Al-Qadim.com
BIRTHRIGHT - CERILIA:
Birthrigh.Net
Cartographer's Guild
Enter the Continent of Cerilia
DARKSUN:
The Burnt World of Athas
DRAGONLANCE:
Dragonlance Forums.com
FORGOTTEN REALMS:
AD&D Unlimited
Dlabraddath - A Celebration of the Goodly Races of D&D
Candlekeep
Forgotten Realms FAQ
Forgotten Realms Portal
Realmspace: Geonomicon
Yet Another Forgotten Realms WebPage
GAMMAWORLD:
The Post-Apocalyptic Forge
GREYHAWK:
Cannonfire! World of Greyhawk On the Web
Dave Arneson's Castle Blackmoor
Maldin's Greyhawk: The Legend of Kyuss
The Griffin's Crier
KARA-TUR + ORIENTAL ADVENTURES:
Oriental Hardpoint
LANKHMAR:
Quest Bird's Nehwon Campaign
Lankhmar: Carnival of Swords
Lankhmar: Fritz Leiber's famous (or infamous) City
Lankhmar Geomorphs
MYSTARA:
Dave Arneson's Blackmoor by Havard
Fahvarim's Lorebook
Harmyn's Dungeons&Dragons - Classic Edition
Marco's Mystara Homepage
Master of Disaster's Mystara Files
Mystara of Rost
Nightlive - The Savage Coast
Principalities of Glantri
Scythe's Mystara Page
The Known World
Vaults of Pandius - The Official Mystara Homepage
PLANESCAPE:
Jenkin's Planescape
Planescape - Welcome to the Mimir
Planewalker.com
The Great Planescape Webring
RAVENLOFT:
Lace Wing's Story - It mentions Ravenloft
Raven's Blood - Only Game patches for various AD&D Computer Games
Realms of Evil - More of a d20 Site Now
The Fraternity of Shadows
The Lonesome Road
The Mordent Cartographic Society
The People of Ravenloft
Vampster's Ravenloft Campaign
SPELLJAMMER:
Realmspace: Geonomicon
Spelljammer: Beyond the Moons
World of Arkaela
OTHER WORLDS:
The Gods of Arr-Kelaan - A Comic
The World of Arr-Kelaan
Nether Realm
McDeath's Compiled Links
Moderator: Hogan