Pesach, the springtime holiday of Passover always begins on the 15th day of the Jewish month of Nissan. This year, this coincides with April 9, 2009. Like all Jewish holidays, Passover begins the evening before, so the first seder is held on the evening of April 8. The basic theme of the holiday is the exodus from slavery in Egypt; the various rituals and texts associated with Pesach help us to establish and understand this crucial narrative of Jewish communal memory. The basic story is found in the book of Exodus, chapters 1-15. Chapters 12-15 contain details of the observance of the holiday itself.
The name Pesach comes from a Hebrew word meaning "to pass through" or "to pass over". It refers to the story of how God "passed over" the houses of the Jews during the plague of the Death of the First Born. "Pesach" is also the name of the sacrificial offering (a lamb) that was offered in the Temple on this holiday. Pesach is also sometimes called the Chag Ha-Aviv "Holiday of the Springtime," or Zman Cherutenu "the Season of our Freedom."
On the first night of Pesach (first two nights for many traditional Jews outside Israel), there is a special meal filled with ritual to teach us the significance of the holiday. This meal is called a Seder, from a Hebrew word meaning "order." There is a set of texts that are to be discussed in a specific order. The Seder also includes rituals of eating matzah and bitter herbs, singing holiday songs, and asking questions. It is a multi-media Jewish ritual event! The texts, prayers and instructions for the evening are found in a volume called the Hagaddah, which means 'telling.' The point of the evening is not to read the Hagaddah, but to use it as a springboard to 'jump off the page.'
We have prepared extensive resources on preparing and leading a Seder.
The most well-known observances of Pesach are the the holding of the Seder meal on the first night (or nights) and the prohibitions against the eating of Hametz - leavened foods. Leavened foods include anything made from five basic grains: wheat, barley, spelt, rye, and oats. This includes anything made from these products, including beer and grain alcohols. The only acceptable way to eat these grain products is in the form of Matzah, or unleavened bread, which is baked very quickly so that the dough does not rise. This helps us remember the speed with which the Israelites left Egypt. The Bible says that they did not have time for their bread to rise. Other kinds of foods can be made from ground-up matzah, including cakes and confections, but these are prepared especially for Pesach.
Jews of Ashkenazic (European) descent often also refrain from eating a category of food called kitniyot. These are products made from seeds and beans, including rice, corn, and legumes. The concern is that the prohibited foods may be confused with these items in processed form. Many Sefardic Jews will eat kitniyot, but customs vary widely.
Biblically, Pesach lasts for seven days, but, since Rabbinic times, many communities observe eight days. The prohibition against eating leavened foods lasts until sundown after the final day of the holiday.