Copyright and Creative Commons can be confusing topics for a lot of people. Fortunately, there are people like Rodd Lucier to help remove that confusion. Rodd created an awesome audio slideshow about Creative Commons called Creative Commons: What Every Educator Needs to Know. In addition to this presentation, Rodd has an excellent podcast series and blog called The Clever Sheep. I encourage you to check out all of Rodd's digital content.
Thanks to Angela Maiers for bringing this slideshow to my attention via her excellent blog.
Here are some related items that may be of interest to you:
When You Use Creative Commons Licensing...
Compfight - Creative Commons Image Search
Copyright for Educators