here's part of a setup method ( i'm working on the project right now ) :

sub setup {
                my $self = shift;
                $self->{TEMPLATEDIR} = "/home/templates";
                $self->start_mode('edit_setup');
                $self->mode_param('rm');
                $self->run_modes(
                        'setup'         => \&setup_list,
                        'edit_setup'    => \&setup_edit,
                        'view_listing'  => \&view_listing,
}
[download]

the start_mode determines what the first value of your run_mode will be.

subs are then executed by URLs like:  index.cgi?rm=view_listing

now go read the  perldoc on it. ;-)