The American Library Association published a Model Policy Concerning College and University Photocopying for Classroom, Research and Library Reserve Use. The Model Policy suggests that the following guidelines be followed for Reserves:
1.The amount of material should be reasonable in relation to the total amount of material assigned for the course.
2.The number of copies should be reasonable in light of the number of students enrolled.
3.The material should contain a notice of copyright.
4.The effect of photocopying the material should not be detrimental to the market for the work.
5.The same material placed on reserve for succeeding semesters must have copyright permission.
6.Copying shall not be used to create or to replace anthologies, compilations or collective works.
7.There shall be no copying of or from works intended to be "consumable." These include workbooks, exercises, standardized test booklets and answer sheets and like consumable materials.
8.Copying shall not substitute for the purchase of books, publisher's reprints or periodicals.
Here are good sites for further information: