If you’re going in cold, I don’t recommend this book just yet.  First brush up on your calculus and linear algebra, which is the mathematical basis for QM.  Then read some popular accounts on QM, such as Ford’s The Quantum World.  If you’re still motivated, then read this book, watch Susskind’s lectures online, and then read the book again.  If you still want to go deeper, then go and study standard QM textbooks like Shankar, Townsend or Zettili and do lots of problems to get proficient.<br><br>My only issue with this book is his treatment of entanglement.  Susskind, bless his heart, is a wonderful teacher and a gift to science, but he blows it here.  He seems to ignore nearly a decade of research on the subject which have proven near-loophole free verification of Bell’s inequality.  His excuse is not wanting to get into the philosophical debates on non-locality.  If he ever issues a second edition, I hope he revisits this critical subject.