Each label uses words and pictures to describe the category of books in that bin :)
I created these to put on book bins in my classroom library. I cut them out, laminated them, and taped them to my book bins. These have helped keep books organized and have assisted students in finding books that interest them.
--my students do a pretty good job putting books back where they found them. If it is a challenge for your students I would suggest putting a dot sticker on each label (or different color permanent marker dot) and putting the same color dot on the books that belong in that bin :)
Hope this saves you some time or gives you an idea of how to organize your classroom library books!