The TEACH Act allows for some use of copyrighted materials for distance education.
In many cases, you can eliminate the need for permission or fee by simply giving your students a link to the work instead of making copies of it.
Fair use is a right! There is no page limit to what is considered Fair Use for teachers. Rather, it is the USE of the item that is at issue. An excellent checklist for instructors to use when considering copyright questions is posted below.
Resources that will help you gain permission to use copyrighted works.