A common question asked, "Is it okay for me to post this reading to my course shell?" It is a question that is often without a clear answer. Fair use is the only copyright exception that would apply to this kind of use so it really comes down to doing a full and honest fair use analysis.
Some things that enhance a fair use argument:
Some things that weaken a fair use argument:
Remember, too, that many articles and even book chapters can be accessed electronically using the library's databases. Providing a permanent link to this licensed content allows you to avoid dealing with copyright issues altogether and, incidentally, might have the side effect of introducing your students to the wide world of library resources!