There are a couple of decent 'pop' books that explain the general ideas. Marcus Chown's "Quantum Theory Cannot Hurt You" is good for an afternoon's entertainment, and after your brain has eased into that, John Gribbin is always a fantastic read. I recommend his "In Search of Schrodinger's Cat". Although he has quite a few.. that's the only one I've read.
But the saying is correct (I forget who it's attributed to): "If you think you've understood quantum theory, you've understood nothing of quantum theory." It's stranger than most things.
Of course, we might not be talking about the same thing - I did a three week module in first year Physics called quantum mechanics.. it was just about electrons and their orbitals etc., loads of Aufbau diagrams.. but nothing wierd and freaky and wonderful.
It's attributed to Richard Feynman. Who also has some good publications on the subject.
Yeah, six easy pieces, well, for me, not so much.....maybe time to try again