For more information about Shabbat, the following resources may be helpful:
Aish Hatorah
National Jewish Outreach Project
The Sabbath - Heschel, Abraham Joshua. The Noonday Press, September 1996.
The Nine Questions People Ask About Judaism - Prager, Dennis, and Joseph Telushkin. Touchstone Books, April 1986. (pp 53-57), (pp159-169).