I can very much recommend the documentation that comes with perl, there are two tutorials for OO: perldoc perlboot and perldoc perltoot.

I learned OO in Perl mostly with these. Simply put OO in Perl is just a reference that has a package name attached (via bless (see perldoc -f bless) to it, allowing Perl to find the methods for that 'reference'. So that you can call the subroutines of the package like this: $ref->test_method (1, 2, 3);.

Hope I didn't confuse you too much now. Just read perlboot and/or perltoot and skim through perlobj for a reference about how to use the OO features of Perl. http://perldoc.perl.org/ is a very useful resource!