What a daunting job! At first I was writing the level of each book, then decided not to level them but just put them in categories. There are so many ways you could categorize books! Ugh! Huge job. Since I am moving down, I am going to have one of my 5th graders from last year come and scan all the books into my Book Retriever app, but first I have to group them! Does anyone else find this job difficult? Do you have a simple answer for me to make it easier? Would you level them? The app actually does that, but it won't be written in the book.