Dungeons & Dragons Online:Official site. Provides news, downloads, FAQ, forums, screenshots, and background.
3D Gamers: Includes information, news, screenshots, and downloads.
DDO Off-Peakers: Provides a forum and guild listings for players who are online during the US off-peak hours.
DDO Wiki: Provides game data, small guides and guild listings.
Dungeons & Dragons Online Europe: Official european DDO site by Codemasters. Features news, an encyclopedia and media files.
FilePlanet: Provides movies, trailers, and game clients.
GameAmp: Offers news, guides, screenshots, and forums.
IGN: Contains screenshots, videos, previews, news, and a message board.
IGN Vault: Offers news, screen shots, guides, trailers, concept art, and fan fiction.
MMO DB: Database for bestiary, items, NPCs, quests, skills, spells, zones and maps.
mmosite.com: Features screenshots, news and game data.
Ten Ton Hammer: Provides news, guides and articles.
WarCry: Offers news, images, and an FAQ.
Wikipedia: Explains background and history, differences to other MMORPGs and planned updates.