S.D.
What a great idea. maybe this would be more fun then us adults . I think I could really see this being fun. I would write out a questionire ( sp ??)
that each child fills out that will guide them to what they will talk about. I would limit it for 20 min of the discussion, 10 min for a snack, and 30 min of play or games or craft to tye it all up. Maybe every 2 weeks or once a month so it is not too much and those that read slower are not so much in a hurry.
Maybe ask the parents to really get involved as far as the behind the scenes. Picking crafts and snacks related to the book.
My daughter loves Nancy Drew, Giramino Stilton, Sleep over squad, Animal Ark are a few. They are a bit easier so maybe make it less hard to read at first and then move in to the more difficult ones.
Good luck !