Once you know about the mailing lists available, you may wish to subscribe to some of them. For this you use the @subscribe command.
@subscribe <*list-name>
This checks that you may read the list, and will then subscribe you. This command has a couple of other useful forms also however:
@subscribe +new
This is the command form used to determine on what lists you have new mail.
And finally:
@subscribe
This merely prints out the list of mail lists you are currently subscribed to.