General references and references for Dirac equation

Quantum Mechanics L. I. Schiff, (McGraw-Hill, New York), 3rd Ed., 1968.

Chapter 13 discusses the Dirac equation.

Intermediate Quantum Mechanics, H. A. Bethe and R. Jackiw, (Addison-Wesley, Reading, MA) 3rd Ed., 1997 ISBN 0-201-32831-3

Chapters 21 - 23 discuss relativistic wave equations and the Dirac equation.

Relativistic Quantum Mechanics, J. D. Bjorken and S. D. Drell, (McGraw-Hill, New York), 1964.

Chapters 1-4 discuss the Dirac equation.

F. Schwabl,  Quantum Mechanics
Concise, well-organized, clear exposition.

C. Cohen-Tannoudji, B. Diu and F. Laloe, Quantum Mechanics
Massive, strong on both fundamentals and applications, excellent for self-study.

L.D. Landau and E.M. Lifschitz, Quantum Mechanics (Non-relativistic theory)
Practical and fundamental, with many applications and worked problems.

G. Baym, Lectures on Quantum Mechanics
Informal but sophisticated, very readable, with many applications.

J.J. Sakurai, Modern Quantum Mechanics
Written by a high-energy theorist, tilted toward the algebraic approach. Nice choice of examples.

E. Merzbacher, Quantum Mechanics
Another ``standard" graduate text, with the slant of a nuclear theorist. Strong on scattering theory.
A third edition came out in 1997.

R. Shankar, Principles of Quantum Mechanics
Holds the student's hand, verbose, mostly elementary,  but has some very nice modern applications.

D.J. Griffiths, Introduction to Quantum Mechanics
A very well written modern undergraduate text,  neatly organized and lucid.

P.A.M. Dirac, Principles of Quantum Mechanics
An elegant classic.

R.P. Feynman, The Feynman Lectures on Physics, vol. III
A ``beginning undergraduate" text offering insights that keep professors coming back.

A. Messiah, Quantum Mechanics
Strong on the formal and mathematical aspects of the theory.

J. Preskill, Lecture Notes on Quantum Mechanics and Quantum Computation
Notes from a Cal. Tech. course. Includes a nice introduction to the fundamentals of QM.

M. Abramowitz and I. Stegun, Handbook of Mathematical Functions
Indispensable for special the days before Mathematica.

Gradshteyn and Ryzhik: Table of Integrals, Series, and Products
The best.