DooM Editing for Newbies
So You Want to be a DooM Editor Tips on how to begin the process of becoming a good, even great, DooM editor.
Getting Started: Tools of the Trade An overview of the utilities available for making maps, editing graphic and other resources, and manipulating the behavior of things in DooM.
Basics of Design and Gameplay A very broad overview of various elements that contribute to a fun map.
What Makes a Good Map Style pointers, including gameplay, architecture, and atmosphere. Also, read this essay by Joel Murdoch.