Here is a picture of my classroom library. I keep the majority of my books on these shelves. I keep these baskets out year round for students to choose from.
All the books are labeled with address labels. The book labels and the outside book baskets all match so students are able to put the books easily away. The labels are available on my website for free here.
In this picture you can see our special books. These are usually theme or seasonal books. Some are from the school library and some are from my "stash" of books. I keep these separate from the classroom library.
I keep my special books in Ikea cardboard book boxes on a shelf above my desk. I turned the book boxes on their sides and labeled the BOTTOM of the book (the label makes the box more stable) with the theme or topics inside. These are the books on the top shelf.
Tada! There is my classroom library and book set up!