Hercules. Disney Enterprises, [1997]. An animated carton very loosely based on the myth of Hercules.
Crane, Gregory R. (ed.) The Perseus Project, http://www.perseus.tufts.edu, April, 1998. The Perseus Project is a digital library of resources about the ancient world. It includes texts, translations and examples of period pottery. It is a collaborative body of work by scholars at a number of academic institutions. It is maintained by Tufts University, Medford, MA. The material is also available in a CD-ROM version published by Yale University Press.
Of particular interest to this study is the following location on the website: http://www.perseus.tufts.edu/Hercules/
It tells the stories of Hercules and includes maps and examples of ancient pottery from museums all over the world which depict various aspects of the myth.
There are a variety of other web sites which show some examples of pottery depicting images from Greek mythology, but the above site is the only one so far identified as showing images directly related to Hercules.
The Yale University Art Gallery owns a collection of ancient Greek pottery. A visit there would give the children an idea of what it actually looked like.