Rosh Hashanah, which means literally "head of the year", is celebrated as the Jewish New Year. On this day, the souls of the departed are taken into account. Into the book of life the names of the righteous are inscribed. Those who are not completely lost are given ten days (till Yom Kippur) to repent and become righteous. The wicked have their names blotted out of the book of life and instead written into the book of death.
Rosh Hashannah is commonly known as the day of sounding [the shofar ~ a ram's horn]. The blowing of the shofar is intended to awaken sleepers from their slumber and warn them of their impending judgement. The shofar is blown in a series of long and short sounds following this sequence:
Teki'ah, a long sound;
Shevarim, 3 broken sounds;
Teru'ah, 9 short sounds;
Teki'ah, a long sound;
Shevarim Teru'ah, 3 broken sounds followed by 9 short sounds.
It should be noted that the name "Rosh Hashannah" does not appear in the Bible. The celebration is referred to as either Yom Ha-Zikkaron (the day of remembrance), or Yom Teruah (the day of the sounding).
Erev Rosh Hashannah (i.e. Rosh Hashannah Eve) begins at sundown on the 29th day of the Hebrew month of Elul, and many Orthodox Jews prepare for the celebration by participating in mikveh, a full immersion in water for ritual cleansing. In order to perform the mikveh, the person first cleans the physical body by showering. Then he/she descends into the pool specially constructed for the mikveh in which the depth of the water reaches the neck. Although the mikveh is similar to the Christian baptism rite, it differs in that the Jewish person is not assisted by another (i.e. a religious officiant). And rather than being dipped backwards into the water, as the Christian is in baptism, the Jew advances forward and downward into the water until completely immersed.
Rosh Hashannah is celebrated in the synagogue with the blowing of the shofar and the reciting of Biblical verses and prayers. Special religious poems of repentance, called "piyyuttim", are recited.
A seder is held during which time special blessings are said over dishes symbolic of the new year.
During the afternoon of the first day of Rosh Hashannah, a ritual known as tashlikh is performed. Participants gather beside natural flowing streams or bodies of water. Prayers are recited, and the reciter's sins are symbolically cast away as they toss pieces of bread or small pebbles into the water.
Rosh Hashannah is a time for making resolutions for the coming year. It is a time for introspection, for looking at the mistakes made during the past year, and resolving to not repeat them in the new year.
A tradition of Rosh Hashannah is the eating of apples dipped in honey, which is symbolic of a wish for a "sweet" new year.
Traditional foods eaten during the Rosh Hashannah celebration include the previously mentioned apples dipped in honey and "challah", a type of braided bread. Pomegranites are also favored during this holiday. A common belief is the symbolic hope that our good deeds will be as numerous as the seeds in the pomegranite.
The celebration of Rosh Hashannah and that of Yom Kippur, which follows in ten days, are collectively known as Yamim Nora'im, the "Days of Awe".