I am deeply in love with "Smalltalk Best Practice and Patterns" by Kent Beck. Its the best book I have read on programming , its clear, 100% practical, straight to the point without unnecessary theories , surprisingly small yet so large . I would recommend it to anyone not just introducing to Pharo , but any programming language out there , OO or not. Some of the concepts should also feel familiar for a functional programmer like you.��
I have not used it only to learn OO but also as a source of inspiration for my projects since it actually a pandora box of cool ideas :)��