Excellent Moose introductions and tutorials

Modern Perl (see also the Modern Perl book) is based on, among other things, Moose as an object system, built on Perl 5's innate but spare O-O abilities.

This introduction [houseabsolute.com] explains not only Moose itself but quickly, and fairly painlessly, brings you into modern object orientation.

Also, Moose Is Perl − A Guide to the New Revolution [oreilly.com] − an over 400-page guide from the introductory to the detailed.