For someone new to database servers and their dependencies, what is the easiest assured way of installing PostGIS on a machine with no other software beyond what comes with its operating system? I'd like to know for Ubuntu, Windows and if possible a common Linux method. I'm understanding that you need to install PostGreSQL first, but before that perhaps you need to install Apache Server, and I'm not sure if that has dependencies.
Perhaps there a single binary that loads EVERYTHING for Windows, and maybe there a single program from the Ubuntu GIS repositories that installs everything. If not, what's the install order?