Megillat Esther, "The Scroll of Esther," is a firsthand account of the events of Purim, written by the heroes themselves--Esther and Mordechai.
The Megillah is read twice in the course of the festival: on the eve of Purim and during Purim day. It is read in the original Hebrew from a parchment scroll.
Print the Megillah out and take it to your synagogue to follow the reading, or use it to study in the comfort of your home.