Perseus Digital Library
This is perhaps the most important single free Web site in the field of classical studies. It supplies the text in Greek, Latin, and (often) English translation of the works of many ancient authors. It also provides the texts of more recent books on aspects of the ancient world, and thousands of pictures of art objects, sites, and buildings. If you do research on the ancient world on the free Internet, and don't check out the Perseus Digital Library, your research will simply be incomplete.