“Deaf” should be capitalized when it is part of a proper title, such as Trenton School for the Deaf. Central should also be capitalized when it is part of a title, such as Central Park in New York City. Central should not be capitalized when it refers to a broad geographical area, although some would disagree with this last. As for the bus question, my dictionary says that “buses” is the preferred spelling and “busses” is second.