There’s a whole lot to learn about Shirley, but there’s no need to feel overwhelmed. Before you climb into your rental car, let’s start off with a few basics.This town sits 12 miles to the northeast of West Sayville, and 255 miles northeast of Washington, the nation’s capital.Facts and figures fascinate you? Want to find out how many people reside in this part of Suffolk County before you go on your day trip? At last count, the population was 27,900.