A list of the currently available mailing lists is available in at least two places; the first is in a file on ftp.nisc.sri.com called interest-groups under the netinfo/ directory. It's updated fairly regularly, but is large (presently around 700K), so only get it every once in a while. The other list is maintained by Gene Spafford (spaf@cs.purdue.edu), and is posted in parts to the newsgroup news.lists semi-regularly. (Usenet News, for info on how to read that and other newsgroups.)
Listservs
On BITNET there's an automated system for maintaining discussion lists called the listserv. Rather than have an already harried and overworked human take care of additions and removals from a list, a program performs these and other tasks by responding to a set of user-driven commands.
Areas of interest are wide and varied—-ETHICS-L deals with ethics in computing, while ADND-L has to do with a role-playing game. A full list of the available BITNET lists can be obtained by writing to LISTSERV@BITNIC.BITNET with a body containing the command
list global
However, be sparing in your use of this—-see if it's already on your system somewhere. The reply is quite large.
The most fundamental command is subscribe. It will tell the listserv to add the sender to a specific list. The usage is
subscribe foo-l Your Real Name
It will respond with a message either saying that you've been added to the list, or that the request has been passed on to the system on which the list is actually maintained.
The mate to subscribe is, naturally, unsubscribe. It will remove a given address from a BITNET list. It, along with all other listserv commands, can be abbreviated—-subscribe as sub, unsubscribe as unsub, etc. For a full list of the available listserv commands, write to LISTSERV@BITNIC.BITNET, giving it the command help.