Wikisource is an online library of close to 300,000 texts, all of which are in the public domain and therefore not subject to copyright restrictions. Texts include government documents along with books, plays and poems from ancient Greece through the early 20th century.

This online exhibit, from the University of California-Irvine Libraries, contains pictures of and information about the writings of the Maya, Aztec, and other ancient Mesoamerican civilizations.

This site covers argument papers, research papers, exploratory papers, book reports, essays for exams, and annotated bibliographies.

"SagaNet provides digital access to the central corpus of the Icelandic Saga literature."

The Perseus Digital Library, created and maintained by Tufts University, is an excellent source for texts and images related to ancient Greece and Rome. Click on "Collections/Texts" to see the other areas covered by the library (there are strong collections of 19th century American history and the Renaissance as well). The full text of many classic Greek and Roman works are online here, including the Iliad, Odyssey, Aeneid, Plato's Republic, and many more.

This online encyclopedia has information about mythology from around the world. A good source for basic background information, and for information on more obscure characters or legends.

The OWL - Online Writing Lab - has excellent resources for the entire writing process, including sample papers, citation examples, resources for ESL writers, and tips for evaluating websites and other resources.