The best blacksmithing stuff on the internet is not newsgroups, but
forums-

http://www.anvilfire.com/
(the guru's den and the hammer in)

http://www.forgemagic.com/bsforum.php

http://www.iforgeiron.com/

then there are a couple of good email lists-

the forge- subscribe at:
http://mailman.qth.net/mailman/listinfo/theforge

and the yahoo blacksmiths group