Your school should have a Board of Education approved policy that covers collection development. This should include policies that cover at least these two topics:
The school selection policy should include how materials are selected, who shall do the selecting, and the eventual removal of these materials once they are outdated.
Usually you can find your school policies at your school website, on the Board of Education page.
The ALA Selection & Reconsideration Policy Toolkit is a very valuable resource for any library. Please check it out.
A good selection policy should include the following:
All library staff, building principals, and other administrators should be aware of the collection policies and procedures. These procedures and documents should be readily available and should be reviewed annually with library staff and building/district administrators.
A good reconsideration policy should address: