Two Sifrei Torah are removed from the aron kodesh.
In the first Sefer Torah, seven aliyos are read in Parshas Tetzaveh. The second Sefer Torah is then placed next to the first one, and Chatzi Kaddish is recited. This is followed by hagbah and gelilah of the first Sefer Torah.
From the second Sefer Torah, Parshas Zachor (Ki Seitzei 25:17-19) is read for maftir. This is followed by hagbah and gelilah of the second Sefer Torah.
According to most Poskim, the kriah of Parshas Zachor is min hatorah. Therefore, when listening, have in mind to be yotzei your obligation.
There is a machlokes haposkim whether women are obligated to hear Parshas Zachor. The Rebbe once mentioned that it has become customary for women to go to shul and hear this parshah.
The baal korei reads zeicher zecher Amalek (first zeicher and then zecher).
The haftorah of Parshas Zachor is then read. The haftorah begins with the words Ko amar Hashem (I Shmuel 15:2).
Although tomorrow is Taanis Esther, as long as you have not yet gone to sleep, you may eat until alos hashachar.
Do not rinse your mouth in the morning (as is usually done before reciting birchos hashachar).
For more fast-related laws, see below, “Hosafos.” On a fast day, it is customary to increase in tzedakah, in quantity as well as in quality (by giving it in a cheerful and pleasant manner).