There are basically two approaches: The first one is to learn postscript, and then use perl to generate the postscript files, presumably with a template system.

The other approach is to to ignore that you have to work with postscript, and instead focus on arbitrary vector graphics, because most of those can be converted to postscript in the end.

For example gnuplot can produce vector graphics, and incidentally postscript is one of its output formats.

For combining multiple graphics into one, consider using ghostscript, it's the postscript swiss-army chain saw.