Answer:
   
   As a reminder, Shabbat runs from sundown on Friday night to sundown on
   Saturday night. However, Shabbat preparations begin well before
   sundown, as one must be ready for the arrival of the "Shabbat Queen"
   (traditionally, Shabbat is treated as an arriving queen).
   
   By mid-afternoon on Friday, traditional begin to prepare. The house is
   cleaned. The family prepares itself for the arrival of a special
   guest. One wears the best clothes that one has (some families have the
   tradition of reserving the first wearing of new clothes for shabbat).
   The best dishes and tableware are set. A festive meal is prepared (the
   running joke is that it is always Chicken :-)). Additionally, one must
   prepare for all those things that one cannot do on Shabbat. For
   example, lights and appliances must be set (or timers set); the
   refrigerator light bulb must be removed or unscrewed; and preparations
   for Shabbat meals must be made.
   
   As the sun is starting to go down, Shabbat candles are lit and a
   blessing is recited no later than eighteen minutes before sunset. Why
   "before sunset"? Because after sunset, one cannot kindle a flame. The
   candle lighting is traditionally performed by the woman of the house;
   it marks the beginning of Shabbat. There are two candlesrepresenting
   the two commandments: zachor (remember) and shamor (observe). The
   family then attends a brief evening service. [In Reform congregations,
   the candle lighting is often done as the first activity in the
   service.]
   
   In traditional households, the family comes home for a festive,
   leisurely dinner after services. In Reform households, dinner is often
   held before services. Before the dinner, the head of the house recites
   Kiddush, a prayer over wine sanctifying Shabbat. The usual prayer for
   eating bread is recited over two loaves of challah, a sweet, egg bread
   shaped in a braid. The family then eats dinner.
   
   In the Reform movement, there is not always a festive dinner. To
   ensure the blessings are said, Reform congregations often have an
   "oneg" after the service; at the start of the Oneg, the blessings over
   the wine and bread are said by the rabbi.
   
   During Shabbat, in traditional households, meals are generally stewed
   or slow cooked items. This is because of the prohibitions against
   lighting flames and cooking during Shabbat. Stews and slow-cooked
   items are OK, because food that are mostly cooked before Shabbat and
   then reheated or kept warm is permitted. Hence, a traditional Shabbat
   food is Cholet, a form of stew. After dinner, the birkat ha-mazon
   (grace after meals) is recited. By the time all of this is completed,
   it may be 9PM or later. The family has an hour or two to talk or study
   Torah, and then go to sleep.
   
   On Saturday, morning Shabbat services begin around 9AM and continue
   until about noon. After services, its time for another kiddush and
   meal. During the afternoon, the family studies Torah for a while, and
   takes some family time together. Often, people walk to the park to
   enjoy the fresh air. It is traditional to have a third meal before
   Shabbat is over as a light meal in the late afternoon.
   
   Shabbat ends at nightfall, when three stars are visible. Shabbat ends
   with a ritual called Havdalah (separation, division). Blessings are
   recited over wine, spices and candles. The spices remind us of the
   sweetness of Shabbat. The candle is then extinguished with the wine. A
   blessing is recited regarding the division between the sacred and the
   secular, between Shabbat and the working days, etc. We then pray for
   Elijah, who will announce the arrival of the Messiah, to arrive (often
   with the song Eliyahu Hanavi). We then wish each other a good week, a
   week of gladness and joy.
   
   Note: This was adapted from a description of a typical shabbat at
   [5]http://www.aujs.com.au/shabbat.htm. A description of the Orthodox
   service may be found at
   [6]http://www.njop.org/html/shabbat_service.html.