I wouldn't use GD or ImageMagick directly, but rather a higher level module like GD::Graph, Lab::Data::Plotter or Chart. I've only used GD::Graph directly (and Gnuplot manually without the Lab::Data::Plotter interface), and found that it's not hard to use, but the quality of the output isn't as high as with gnuplot or (xm)grace.

You can also search on cpan for plot, chart or graph.

As to installing the modules, try the Super Search on this site, search for windows and module or something, there are dozens of threads about installing modules.