As usual in UNIX, there are many different ways and methods to find the desired information. Useful commands are man, apropos, whatis, and info. Info was treated in the emacs section 3.
A great new source of information is the WWW. Using the search-engines such as AltaVista, Lycos or Infoseek, it is surprising how much material can be found on a topic in very little time, provided that you know the syntax of the search-engine and that you enter precise criteria.