When we use the phrase "newsgroups", we are nearly always talking about the Usenet newsgroups. Even this is somewhat of a misleading phrase... well, Krazy Dan digresses. On your TSX system this can include local "forums" (we use this term interchangeably with "newsgroups") and Fidonet echoes as well.
There are really three clean divisions of information about problems related to newsgroups: incoming news, outgoing news, and issues related to the setup, files, and management of the news on your system. So let's split off here with links toward something ole K.D. has has waxed eloquently about so far: