Slow down for now and let the kiddos do it!
I agree with Fairydust. Just put all of the books on the shelf for now and attend to more pressing matters. At some point get a few baskets (maybe dollar store, your garage, mom's attic, whatever) and have the students slowly organize the books as the year progresses. I did this a few years ago and I'm all organized now. My books are separated by AR level. I made some labels on the computer that say:
Mrs. Taylor
AR Level:
Points:
I found that I could get two book labels out of one sticky regular size mailing label if I cut them in half.
And as each student looked up the level on arbookfinder.com they wrote in the information and put it in the correct basket. They loved doing it when they were finished with their work and I didn't have to worry about it! Hope this helps!!