Wikimedia
Wikipedia: Maya Religion
The structure of Mayan religion is outlined, covering beliefs, the priesthood, rituals, sacrifice, gods, etc.
Wikimedia
Wikipedia: Maya Civilization
Extensive information about Maya history and civilization covering a wide range of topics.
Wikimedia
Wikipedia: Tzolk'in
The Tzolkin is another name for the Maya calendar. The meanings of the symbols on the Tzolk'in and various interpretations that are given to the calendar are outlined here.
Other
Jaguar Sun: The Maya
A large amateur collection of pages on all the major areas of Maya life and culture.
University of St. Andrews (UK)
University of St. Andrews: Mayan Mathematics
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.
Other
Mayan Calendar
While brief, this simple explanation of the Mayan calendar may clarify for some how its two cycles work together.
Curated OER
Calendar Cycle
While brief, this simple explanation of the Mayan calendar may clarify for some how its two cycles work together.