What is an effective way to copyright my teaching material?
To be clear, I am developing the materials while not teaching any courses or being paid by the school in any manner. It is currently the summer semester and I am not being paid to teach, develop course work or anything. I will have to try and find my contract.


The shows a misunderstanding about the nature of a teaching job. When you're paid to teach a course, you're not being paid to do work only while the course runs. You're also being paid to prepare the course, and you're going to need to do that before the first meeting.


  I have finished all of my course materials (.pdfs, lab sheets, power points, etc etc). When I was first hired and told to create the new course, I was informed by some of my colleagues (former adjuncts at the same institution) that I would be paid for my course content. However, in speaking with my directory I was informed that I would not be paid for my course content as it is part of running the class.


Your colleagues were probably confused. Nobody pays instructors extra money to produce powerpoints and handouts. It goes with the job.

If you don't want others in your department to use your lab handouts without paying, don't give them your lab handouts. If you don't want others in your department to use your powerpoints without paying, don't give them your powerpoints. 

As Bill Barth and JeffE have pointed out, copyright protection is automatic in most jurisdictions. It can be wise to put a copyright notice on your work, since a possible defense against a copyright-violation lawsuit is that the defendant didn't know it was copyrighted. A formal copyright registration is necessary in the US if you want to be able to recover more than actual damages, i.e., if you want punitive damages.

In general, the question shows an unrealistic set of assumptions about what teachers do; what they're paid to do; and what the normal contractual arrangements are. Furthermore, many people who write have an unrealistic belief in the quality and market value of their writing. There is no particular reason to expect that anyone else in the department will like these materials so much that they would want to use them. Most people prefer to do things their own way.