Wolfenstein Fun - Related Links
Some wolf3d related links I have found very useful include:
Mr. Lowe's Wolf-3d Page - Tons of cool information here, including new addons, utilities, different platforms for the game, etc. This site has existed for around 10 years and is still being updated frequently with new information!
3d Realms - 3d Realms (originally Apogee) official homepage. They are still distributing the game for $15, and the hintbook for a low price of $2.
DiehardWolfers Forum - Great place to talk about anything wolf3d related. The most active place for discussions about the game, with over 100 members!
ID Software - The homepage of the creators of wolf3d, Doom, Quake, Commander Keen, and many other fun games of the early 90s / shareware era.
John Romero's Site - One of the creators / programmers of the game, who updates his site frequently, and is very active in replying to messages on his forum.