Website
Canadian Museum of History

Canadian Museum of History: Maya Civilization

For Students 4th - 8th
Lots of information about many facets of the Maya civilization. Covers the history, people, geography, languages, cities, society, cosmology, the calendar, and lots more. Includes a glossary and a timeline.
Article
University of St. Andrews (UK)

University of St. Andrews: Mayan Mathematics

For Students 9th - 10th
After a historical introduction, this site from the University of St. Andrews provides information about the mathematics of the Maya Civilization and shows just how advanced they were.
Website
Other

Maya: Astronomy

For Students 9th - 10th
This personal site provides a description of the Maya and their astronomy.