If you got to this guide, you are probably looking for images that you can reuse for some purpose. VCU has many databases that are useful for locating images, but depending on how you plan to reuse the image, you may need to seek out permission from the copyright holder or to use an image that does not require permission to reuse.
The first part of this guide describes copyright and when you would need and would not need to seek permission.
The second part has links to locate images -- under copyright, under Creative Commons Licenses, and in the public domain.
The third section of this guide has some information about citing images in AMA, APA, Chicago, MLA and other citation styles.