Genisys 2:3 And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made. Exodus 20:8 Remember the sabbath day, to keep it holy. This is why the name "Sabbath" school.
these are links to current Sabbath School studies online
Another companion to the Sabbath school lessons is from Amazing Facts
Come and Reason Ministries