SCO has made several Unix versions: Xenix, Open Desktop, Open Server, and Unixware. The SCO Unix 3.2v4.x and the 3.2v5.0.x versions are very similar, so articles in this directory cover both of these.
SCO Unix is basically a Sys V Unix with some BSD additions. If you are accustomed to SunOS or Solaris, SCO will seem to have odd commands and directory structures (see New to SCO Unix for some basic orientation).
Sco is, of course, involved in a nasty and ill-advised lawsuit with IBM.
I no longer follow SCO closely so you probably won't find much new here.
It's way past time to move off SCO. This article provides a list of resources to help with that.