At the school I work for we use a reading program that has different levels of reading books. I have made reading baggies which are on their level according to a reading accuracy and comprehension test that the students take. Each child will get a gallon baggie with their name written on it. Inside the baggie they will have 20 paper books on their level. I use this paper to track the books. I have made 5 copies of each book for 5 sets of each book. (example: Level H- Book 15. 5 copies of Carlos Goes to School.) Each set has all 20 books in the labeled baggie. This works great for silent reading and reading groups as they just bring their book baggie and they all have that book in their baggie.