MSIE 3's built-in newsreader is horrible. Don't put yourself through that torture. Newgroups are hierarchical, that is, the name of a group begins with a general category, and becomes increasingly specific. I will mention below. Includes genealogy, ethnic groups, religion, support groups.
History is here too, rather than under humanities.
Big 8 groups are carried on most news servers, and must pass a formal proposal, discussion period, and a vote to be created. Most soc groups are moderated, because they intend to support the topic discussed. Most other groups are unmoderated. It is much easier to create an alt group than a Big 8 group, but alt groups are not guaranteed to be carried on as many servers. In particular, many news admins refuse to carry alt.binaries.