What is copyright?
Copyright gives you rights over your "original work of authorship." It allows you, the author, to decide who can and cannot copy (i.e. publish) your work.
How do I copyright my work?
Copyright law was rewritten in the 1970s so that anything you write is automatically copyrighted.
How do I get an official document of copyright?
If you would like an official form declaring your ownership of a work, you may obtain one through the US Copyright Office http://www.copyright.gov/.
Is stuff on the Web copyrighted?
Yes. Text, images, web page design, etc. is copyrighted even if you can easily copy it off the web. Unless the material is in the public domain or protected by a copyright alternative like a Creative Commons license you may not use it without permission.
What if I put my stuff on the Web and it gets stolen?
Unprincipled Internet publishers may scrape sites of content and re-post the material without your permission. While annoying this generally does not have a significant economic impact on the author whose material is stolen. Sometimes a simple email will prompt the offending party to remove the work they've taken. In more serious cases you must contact the owner of the website with a DMCA takedown notice. The time and effort you put into a work will probably correlate with the time and effort you want put into protecting it from theft. A blog post isn't probably worth the effort, whereas a story, chapter, or movie you've worked on may require more serious measures.
What can NOT be copyrighted?
Titles, short phrases, works already in the public domain, other people's works (without their permission) and ideas.
What are alternatives to copyright?
Sometimes you may want to make your work available for others to use. You can apply a Creative Commons license to your work which allows others to use your work within parameters you set.
Why would I ever NOT want to copyright my work?
Some artists see obscurity as their biggest hurdle. By allowing others to use their music, images, or text freely (but often requiring some type of attribution) they believe their work has a better chance of becoming known. Some authors also allow some of their work to be freely reprinted, believing that providing some free content will attract attention for their other work which is for sale.
What are some good resources about Copyright?
Where can I learn more about Creative Commons?
At the Creative Commons site.
Where can I learn more about the Public Domain?
Wikipedia has an excellent introduction to Public Domain.
Is the work I do while a student of the University considered "work for hire?"
No. Students own the copyright of everything they produce while in their role of student at the University. If you are a student worker and asked to write a pamphlet on the policies of your department as a part of your job, then that may be considered work-for-hire, and the copyright would belong to the University.
What is work-for-hire?
In some cases, the writing (or other creative project) you produce, will be owned by your employer. This typically only applies for work-related projects like policy manuals, brochures, job-related website content, etc.