Yes. We know. You don't like to hear that word: Copyright. Believe us, it's more complicated than you think, and it's constantly changing, especially in this digital world. We can't advise you as to whether something violates copyright or not; that's up to the attorneys (who make a lot more than librarians or instructors!).
However, here are some tools that will help you make those decisions yourself.
(One recommendation: it's generally safer to link to an article/item than reproduce the article/item itself).
P.S. All of the tools below fall within the creative commons license. Thanks to the American Library Association!