It has been a long time since I attended a Bat Mitzvah and I have to say I wish all young teens could participate in such a wonderful welcome to adulthood! Today we have had the pleasure of sharing one and it has been a great day!
When a young girl becomes a Bat Mitzvah (daughter of the commandment) at age 12, she becomes a responsible female and takes her place in the congregation as (more or less) an adult - with all privileges and obligations, therein. Preparation includes at least a year studying Hebrew, as well as Jewish history and traditions, usually in a class with others coming of age in that year.
A young girl actually becomes a Bat Mitzvah when she turns 12 and there is no ceremony required, but in fact ceremonies and parties with families and friends are very common in non-orthodox communities. During the ceremony held with a regular Shabbat morning service of prayers, blessings and songs, the new Bat Mitzvah affirms her new role by leading parts of the ceremony, blesses the Torah for the first time as an adult, chants from the Torah and Haftarah, and leads a discussion about a Torah reading.
Torah means teaching, and the Torah is a parchment scroll containing the first five books of the bible. The Haftarah is a reading from the second section of the Hebrew Bible know as Prophets. In orthodox communities if the bat mitzvah wants to read from the Torah and lead a ceremony, it is done with women only.
In some congregations, the focus is on service to the community and there is a large project done like raising money for a nonprofit organization during the year, and many girls will ask for canned food donations collected before the Shabbat. If there is a party later in the day - get ready to celebrate and bring a gift - clothing, music, and frequently cash, in multiples of 18, as the Hebrew word for life (chai) has the numeric value of 18 in Judaism.