Take immediate steps to meet with the parent or teacher who issues the challenge on a book. Ask them to explain their concerns in detail. Listen.
Explain to the person who issues the book challenge why that particular book is on the library shelf. Show the person reviews of the book. Also explain how the book is a part of the school's curriculum.
Show the concerned parent or teacher examples of book challenges for that particular book in other schools. The American Library Association offers a vast array of reviews of challenged books on their Web site. They also offer guidelines for protecting everyone's intellectual freedom.
Provide the person making the challenge with a "Reconsideration Form." Ask them to complete it so you can begin the reconsideration process. While many parents or teachers are willing to forget their original challenge by the time they get to this step, if a parent feels he must get the book removed from the shelf, this is the next step.
Leave the book on the shelf. Until a book review committee votes to remove the book from the library, it should remain in circulation.
Arrange for the book review committee to meet. Your library's collection development policy should have specific guidelines as to who sits on this committee as well as their powers.
Remain calm throughout the entire process. The challenge is against the book, not you.