Learning a bit of Quantum Mechanics is going to be more helpful than anything else in physics to understand quantum computing. Introduction to Quantum Mechanic

Learning a bit of Quantum Mechanics is going to be more helpful than anything else in physics to understand quantum computing. Introduction to Quantum Mechanics by Griffiths is a standard undergrad text. The math is all "simple" (linear algebra and calculus). It's the learning a new way to think about the world that's the hard part.