ABSTRACT
The purpose of this introductory chapter is twofold: to list the prerequisites the reader needs to understand the book and to tell what material is in the rest of the book.
It is assumed that the reader is familiar with the basic properties of divisibility, congruences, prime numbers and multiplicative functions. After Chapter 2, we assume the reader is familiar with the Legendre-Jacobi symbol (a/p). Occasionally we will mention related results and give alternate proofs that require a little algebra or analysis, but these may be omitted without loss by the reader having only minimal prerequisites. The books by Hardy and Wright [52], Niven, Zuckerman and Montgomery [79] and Uspensky and Heaslet [113] are good general references for the entire book.
