The Kingston Public Library is forming a book discussion group that will hold its first meeting on Sept. 13 to discuss Geraldine Brooks’s novel “Caleb’s Crossing.’’ The adult readers group will discuss classic and contemporary literature, with an emphasis on literary fiction, said library director Sia Stewart. She noted that Brooks comes from Martha’s Vineyard “and is definitely a favorite of a lot of people.’’ “Caleb’s Crossing’’ is based on the true story of Caleb, the son of a Wampanoag chieftain, who becomes the first member of an indigenous nation to enter Harvard, which then was devoted to training ministers. Future readings will be decided by members of the discussion group, which will meet on the second Thursday of each month from 5:30 to 8 or 8:30 p.m. Participants must preregister by Sept. 12 for the initial meeting, either at the library by calling 781-585-0517, ext. 112, or through kingstonpubliclibrary.org.