Ha, thanks for the shoutout, Dave. Not sure about Wolfenstien, but there are tons of free DooM (original) resources available, which doubtless will have something appropriate. Here's one with a BSD
If you want to sell your game, you'll probably need to read up on licenses, and I'm not even going to pretend to know the ins and outs of them.
Hmm... this might be what you're looking for, too: http://www.areyep.co...reLibrary.html.
(has both tutorials and some textures posted). Couldn't find anything about licensing, looks like they are open for anything.
EDIT: can't use words good
: Fixed broken link