Releasing a wad

Say I've created a full wad with maps, graphics, sounds and music and everything and want to release it so that zdoom (or I am assuming any other doom program) can run it. Is the .wad the only file I need to include?

Almost everything. If you plan on uploading it to the /idgames archive, you'll want to make a txt file and check a few things. Read #6 and 8 if you haven't already:

http://www.doomworld.com/vb/showthread.php?s=&threadid=31922