You can order a box of books from this site. They will range from toddler to young adult books. Each box contains approximately 55 lbs (give or take). You can also order more age/grade specific books, but it costs a bit more.
27 Ways to increase family involvement in your class - Could you try JUST TWO of these strategies before the end of the school year? How about one & plan to adopt another new one for back to school? You know there's room for more family involvement.