The important thing to remember about using Creative Commons Licenced materials is that you do need to attribute the creator.
Attribution is similar to citation. In attribution you need to mention the author, the source, link to the image and cite the kind of Creative Commons licence the material was released under.
Academic citation styles should also be used in addition to attribution for academic and assignment projects, when defined as part of course requirements.
To help you with making Creative Commons attribution, there is a handy tool called the Open Attribution Builder:
Here is a photo. Following it are some examples of how people might attribute it.