Big Brothers Big Sisters of York and Adams County will hold orientation sessions 6 p.m. April 18, noon May 8 and 10 a.m. May 19 at BBBS York office, 227 W. Market St., York. The meetings are for adults interested in volunteering to become mentors for children in the community. Registration is requested but not required. For details or to register, call 717-843-0051.