Lower Grades Learn About the Library from the Shelf-Elf
Jackie Mims Hopkins http://www.jackiemimshopkins.com/ writes really fun books about libraries. In the book The Shelf Elf, the students learn how to use shelf markers and all sorts of cool library manners... in the Shelf Elf Helps Out, they learn about different "library neighborhoods" and why books are grouped together by category. This very introductory lesson helps the students know that there is a method to where the books are placed on the shelves and the importance of keeping the books in their correct "neighborhood" so they do not get lost.