usenet group info needed

["john.gianella" <john.gianella@worldnet.att.net>]

I'm computer literate, but I can't remember how I got into this newsgroup in the
first place.  This goes back about 5 years when I remember looking up subjects
somewhere on the Internet and just clicking on the group to become a
subscriber.  How does one do it nowadays.  I need to become part of some new
groups.  Thanks