Copyright protection covers both published and unpublished works as well as out-of-print materials.
Facts, ideas, procedures, processes, systems, concepts, principles or discoveries cannot be copyrighted. However, some of these can be protected by patent or trade secret laws.
Copyright protection currently lasts for the life of the author plus 70 years. If there is more than one author copyright protection lasts for the life of the last author's death plus 70 years. Copyright protection for materials created by a business may last for 95 years from publication.
Memorandum on Copyright Law and Compliance was written for the University of Nebraska four campuses. It is the responsibility of all faculty, staff, and students to abide by the guidelines presented and utilize the Fair Use Checklist to ascertain if copyrighted materials are being used "fairly" for education and research purposes. Click on Copyright Term and the Public Domain in the United States for more information.
It is always important for an instructor to analyze how he or she will use a particular work to ascertain if their use will qualify under the "fair use" rule of copyright law.
U.S. Copyright Office provides a fact sheet
“It’s important to understand that these aforementioned factors are only guidelines that courts are free to adapt to particular situations on a case by case basis. In other words, a judge has a great deal of freedom when making a fair use determination.” 
If you plan to incorporate copyrighted works into your course ask yourselves these two questions:
- Has the material you have taken from the original copyrighted work been transformed by adding new expression or meaning (or did it just repeat the work for the same intent and value as the original). [1;2]
- Was value added to the original by creating new information, new aesthetics, new insights, and understandings? (ex: satire). 
If your answers are "No" then the "fair use" rule will most likely not apply; so, if you want to show, share, or require students use copyrighted materials you should contact the library: Sally Bryant: Sally.Bryant@pepperdine.edu
 Code of Best Practices in Fair Use for Academic and Research Libraries.
 Stim, Richard, "Measuring Fair Use: The Four Factors." Stanford Copyright and Fair Use Center. Stanford University Libraries, 10 Apr. 2017. Web. 02 May 2017. http://fairuse.stanford.edu/overview/fair-use/four-factors/
Some things to consider about sharing articles.
Your publishers want you to share responsibly; which requires knowing what you may share and where (which is not the same for every publication).
Open Access label indicates you can share according to the end user license:
DIGITAL COLLECTIONS COPYRIGHT POLICY
All materials in these digitized collections are publically accessible and intended for educational and research use, and may be used as such with appropriate attribution. However, organizations and individuals seeking to use digital materials for publication must contact Pepperdine University Libraries Special Collections and University Archives. Such parties furthermore assume all responsibility for identifying and satisfying any claimants of copyright.
Transmission or reproduction of materials protected by copyright beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owner. Responsibility for any use rests exclusively with the user.
Pepperdine University has exhaustively researched the contents of these digital collections to ascertain any possible legal rights embodied in the materials. In cases where copyright holders could not be reached or identified, the materials are provided here under an assertion of fair use (17 U.S.C. 107). We are eager to hear from any copyright owners who are not properly identified so that the appropriate information may be provided in the future. Upon request, we will remove material from public view while we address a rights issue.
Guidelines for Print Materials:
Guidelines for Using Multi-Media
Multimedia works are created by combining copyrighted media elements such as motion media, music, other sounds, graphics, and text. It is recommended that you use only small portions of other people's works.
What is considered a small portion?
The following guidelines allow you to use multimedia without permission of lawfully acquired copyrighted works.
Guidelines for Images
Fair Use Guidelines For Digital Images provides useful information for assessing fair use of digital images.
Code of Best Practices in Fair Use for Media
The Center for Social Media in the School of Communication at American University, the Program on Information Justice and Intellectual Property in American University Washington College of Law, and the Media Education Lab of Temple University are conducting a project 2007-2009 to clarify fair use in media education, with support from the John D. and Catherine T. MacArthur Foundation. This project will help media literacy educators understand their rights under the doctrine of fair use in order to help them more effectively use media as an essential part of their teaching.