Loading reading material into CourseWork or any other course management system is legally equivalent to creating a printed course reader. Where the material is available electronically from a legitimate source (through a library database or the publisher’s website, for example), the most cost-effective approach is to provide a link to the material, rather than loading the file into the course management tool. Linking is not "copying," and thus does not require you to pay licensing fees.

Prior to digitizing copyrighted materials, faculty should review Stanford Libraries' electronic holdings to determine if a pre-existing license for the content exists. Stanford Libraries has secured licenses to tens of thousands of online works, and many others are publicly available (e.g., through Creative Commons licenses). Additionally, there are a number excellent digitization projects, such as Google Books, the Internet Archive, and HathiTrust that are making public domain content available online.

If you must load a copyrighted document into the system, you'll need to pay appropriate licensing fees for distribution of the material to your students. Stanford does not currently have an automated method to pay those fees (though SUL is investigating tools to make this possible), so you'll need to reach out to the Copyright Clearance Center or directly to the publisher to pay. 

This recent presentation to Stanford Law School staff covers a variety of issues related to creating online course readers.