Many kinds of images can enhance you paper, not just sculptural representations of your subject person. Vases, coins, and architecture may all represent objects or events related to your topic.
The following link takes you to a site with great examples of how to cite images using Chicago Manual of style in your papers. You can also consult the Chicago Manual in sections 12.31 - 12.51 for directions on how to write captions and credit lines.
This list provides links to the most common image search engines. Both Google Images and Tin Eye allow you to do a reverse image search by using the image rather than text to find similar or better images as well as more information.