Women are normally exempted from Miṣvot triggered by time, like Tefilin or Sukka, but listening to the Megila is an exception. Because (i) women were part of the miracle, i.e., were also saved from the danger and (ii) it was a woman, Queen Esther, who had the most critical role in saving the Jews from extermination.
Children are not obligated to listen to Megilat Esther, but they are expected to attend Synagogue during Purim. Parents should make sure that their small children do not disrupt the public reading of the Megila.
qera-ah lemafrea' lo yaṣa: "If one reads the Megila in a reverse order, the reading is invalid". Literally, this means that if a person reads first verse 2, then verse 1 and then verse 3 or so, he did not fulfill his obligation. Practically speaking, if a person comes late to the Synagogue and the congregation is reading for example, chapter 4, he cannot say: "I will read now from chapter 4 till the end and then, when they finish, I will read from the beginning till chapter 4". One has to listen or read the Megila in order from the beginning to the end.
During the day of Purim--Sunday Feb. 24th--we send two presents to one or more friends. These presents consist of food, ideally food to be used during the Purim banquet. It is customary to include at least two different types of foods, a drink and a baked product. The intention of this Miṣvot is to promote friendship and strengthen our unity. Mishloaḥ Manot should not be given before Purim or during the night. The Manot should be delivered during Purim daytime. In certain circumstances, Mishloaḥ Manot could be also a very discreet way to send food to those who need it, but would feel very uncomfortable to ask or even receive charity (or matanot laebiyonim) from others.
WATCH Purim Animated See the Purim story come alive, from Aish.