Seasons for Celebration: A Contemporary Guide to the Joys, Practices, And Traditions of the Jewish Holidays by Rabbi Karen L. Fox and Phyllis Zimbler Miller (with illustrations by Vicki Reikes Fox) begins:
It has been said that more than the Jewish people have kept Shabbat, Shabbat has kept the Jewish people. Shabbat, the Sabbath, links us to the past, to all Jews who celebrated this weekly holiday in different countries at different times. Today, it ties us to Jews who speak a myriad of languages throughout the globe. It is a continuing Jewish link in time.
Shabbat, beginning each Friday evening at sunset and concluding Saturday evening at sundown, means different things to different people …
And see the section on ritual hand washing for Shabbat and holidays added in the appendix of the 2008 edition.