I have been teaching for more than 20 years, so I have a large classroom library. All books are in baskets, most of which I purchased from Really Good Stuff. I divided the library into different sections and color coded each section based on the type of book using different color baskets and labels. I have all non-fiction books in white baskets by topic, such as reptiles, human body, soccer, and art. Then I group those topics into sections, so all the animal baskets are on one bookshelf, and all the science related books are on another shelf. Fiction books are in green baskets by genre, and I also have purple baskets with books by one author in each basket. There are also smaller baskets with series books organized with one or two series in each basket. I put chapter books in smaller baskets and picture books in large baskets facing horizontally so students can see the titles.