Doom Wiki
- Community knowledge base, including game information, trivia, technical articles, strategy guides, information about WADs, and editing tutorials.
- http://doom.wikia.com

Planet DOOM
- Articles, screenshots, modifications, maps, and forums.
- http://planetdoom.gamespy.com/

Old Doom
- Offers gameplay guides, cheats, levels and level editing tips for the early doom games.
- http://www.olddoom.com/

exl
- Personal site with new levels and utilities - including WhackEd.
- http://www.teamhellspawn.com/exl/

Team Hell Spawn
- Doom II WADs, forums, and links.
- http://www.teamhellspawn.com/

ReX's Nexus
- Personal site with news of projects the author is working on. Contains downloads of completed projects and some editing guides.
- http://doomnexus.50megs.com/

MancuNET
- News site with discussion forums and interviews. Also hosts various projects and personal sites.
- http://mancubus.net/

Doom 64 for Nintendo 64 at GameSpot
- Review by Jeff Gerstmann, [4.8/10]: "Sigh... yet another mediocre N64 game."
- http://www.gamespot.com/n64/action/doom64/review.html

Doom 3 Forums
- Discussion about all versions of the game.
- http://www.doomforums.com/

Linux Doom FAQ
- A guide to playing on Linux systems.
- http://www.gamers.org/dhs/helpdocs/Linux-DOOM-FAQ.html

Doom Connector
- Service for setting up multiplayer games.
- http://www.codeimp.com/connector_info.php

ClassicDOOM.com
- Walkthroughs and guides, game comparisons, passwords, and links, for all versions.
- http://classicdoom.com/

Doom Collector's Edition
- Review by Kevin Giacobbi , [6.0/10]. "Any serious First Person Shooter should have this as part of their collection."
- http://www.gamezone.com/gzreviews/r19192.htm

Doom Gamer
- Information, discussion and downloads, for classic Doom and Doom 3.
- http://doom.gamer.hr/

DoomGate
- Home of the FAQs for the news groups, the Official Doom FAQ, and some editing guides. Also home to the idgames archive which contains large numbers of add-ons and editing utilities.
- http://www.gamers.org/doomgate/

Lee Killough's Doom Page
- History, trivia and technical information. Includes pre-launch press releases and public alpha and beta releases.
- http://www.rome.ro/lee_killough/

The MJ Doom Page
- General information about the games. Includes links to the FAQs, spoilers, add-ons, and utilities.
- http://www.sonic.net/~mortlgrn/doom.html

Doom Underground
- Help for beginners. Also collected add-ons, utilities and FAQs.
- http://www.nitrorc.com/doomug/

The Doom II Room
- Original levels and a getting started guide to editing. Also a favourite WADs list.
- http://www.users.waitrose.com/~sharx/

NewDoom
- News, interviews, resources, discussion forums, and hosted projects.
- http://www.newdoom.com/

Master Levels FAQ
- Information about the Master Levels add-on pack from id Software.
- http://www.cultmovies.dk/mlfaq102.htm

Parker Information Resources
- Contains news, links, downloads, and game information.
- http://www.parkerinfo.com/dmdo/indexd01.htm