You will want to read the perlboot and perltoot man pages for more information on perl object oriented programming. They should have come with your installation of perl, if not then you can find them here http://perldoc.perl.org/index-tutorials.html. Another good source of information on object oriented perl is the book Object Oriented Perl by Damian Conway.

For the modules that do graphics, there are quite a few. The most common two are GD and Image::Magick.