I'm not sure how useful it would be, but what about 'It's the Great Pumpkin, Charlie Brown?' I don't remember how exactly the story line goes, but I always remember that being a Halloween classic when I was little. It may be worth checking out to see how appropriate it would be for the age level as well as the school. I don't know if they would have anything related to the material, but you may also want to lookinto the VeggieTale books. My kids love those. They are Christian based, but like I said, I'm not sure if they would have anything relating to Halloween material. Or maybe "This is the Pumpkin" by Abby Levine. I haven't personally read them all, but I found those through a search at waldenbooks.com. If I find anything else, I'll be sure to let you know!