Nassau County libraries will participate in The Great Giveback on Oct. 19, and each library hosts a special activity. Visit Oceanside Library any time from 9:30 a.m. to 4:30 p.m. to write letters and decorate cards for service men and women stationed overseas. Visit Island Park Public Library from 11 a.m. to 1 p.m. to paint a wooden star with a message of hope.