Perl6 will be, but if you have little or no prior exposure to OOP I cannot recommend Perl5 for this purpose. (For purposes other than learning OOP, Perl5 is of course wonderful.) Python perhaps, though I personally found Python not to be to my taste.

My favourite book for learning the principles of OOP is the Inform Designer's Manual. The problem domain that Inform is designed to solve (besides being very interesting and providing an excellent didactic framework in general) lends itself spectacularly well to an OO approach, unlike the highly contrived examples in many books, and Graham Nelson is a superbly talented writer.

The only thing is, the book is compiled in the wrong order for this purpose, so you'll want to skip the early parts (about the procedural portions of the Inform language, arithmetic expressions, loops, and so on) and instead go straight to reading the chapters that cover the OO stuff. (The book can be understood just fine in this order, and in fact used to be ordered more this way in the third edition. But you want the fourth edition, because it has many improvements.)

The fourth edition is available both online and in dead tree format.