Teachers and education professors suggest various nonfiction and fiction books for summer reading enjoyment, from Robert Putnam's "Bowling Alone," C.A. Bowers's "Let Them Eat Data," and Larry McMurtry's "Roads: Driving America's Great Highways" to Kent Hauf's "Plainsong, J.M. Coetzee's "Disgrace," and Michael Cunningham's "The Hours." (MLH)