Copyright is not an easy subject, and it only gets more complicated as you factor in questions of fair use for educational purposes. Copyright, and more specifically fair use, has points on which it is specific and unbendable, and other points where there is gray area and interpretation. It is the attempt of this page to try and break down the basic information for you and provide a little bit of clarity, while also providing links to official, legal documents that cover these issues.
Copyright, as defined by the US Copyright Office's Copyright Basics (pdf) is "a form of protection provided by the laws of the United States (title 17, U. S. Code) to the authors of 'original works of authorship', including literary, dramatic, musical, artistic, and certain other intellectual works. This protection is available to both published and unpublished works." [Emphasis mine] In short, it is the right by the work's creator to have reasonable expectations of control over their work and, to various degress, derivative works from it.
It is invaluable to view copyright information directly from the source. Below are links to the US Copyright Office's official documents.
If you feel adventurous, and want to see the source of all this confusion (which just so happens to be vital in sorting out artist and creator rights at the same time), then the complete, 350 page, Copyright Law of the United States and Related Laws Contained in Tıtle 17 of the United States Code is recommended. If a large PDF doesn't fit your reading schedule, the Copyright website has it broken up by chapters.
Moral rights deal more with the use and development of the work and can be even trickier than your average copyright. Moral rights deal with factors of whether the author wants a worked published (including the continuation of publication for an already published document) and how the author wants to be attributed. Moral rights, for instance, allow an author to use a pseudonym or to declare a movie a Alan Smithee production. As far as most class assignments go, the number one thing to keep an eye out for is the moral right to not have a work "distorted, mutilated, or modified" in particular ways. You can read this in section 106 of Title 17 (i.e. The Copyright Code).