Sites written by the people of the tribes themselves are the best sources. We want to learn from the people themselves, not by others who might misunderstand or misuse their culture and history. The citations of each site are below. Please cite each source that you use by copying and pasting the citations you were given here.
The Confederacy: https://www.haudenosauneeconfederacy.com/
The Onondaga: https://www.onondaganation.org/
https://indigenousvalues.org/about/ (This site offers info on culture and values from an Onondaga perspective)
The Mohawk: https://www.srmt-nsn.gov/culture_and_history
The Oneida: https://oneida-nsn.gov/
https://www.oneidaindiannation.com/history/
The Cayuga: http://cayuganation-nsn.gov/tribal-history.html
The Seneca: https://sni.org/culture/
These articles are written from the perspective of people who are not members of the five nations. As often as possible, they are written by or sponsored by those who work to lift up the nations and provide information in alliance with them.
Cultural Survival on the Mohawk: https://www.culturalsurvival.org/publications/cultural-survival-quarterly/mohawk
Smithsonian Museum of the American Indian Haudenosaunee Educator Guide: https://americanindian.si.edu/sites/1/files/pdf/education/HaudenosauneeGuide.pdf (Note: Pay most attention to the cultural and historical information at the beginning, not the activities at the end).
PBS.org on how the confederacy shaped US government: https://www.pbs.org/native-america/blogs/native-voices/how-the-iroquois-great-law-of-peace-shaped-us-democracy/
Iroquois Consitution -- Primary Source Document in Fordham's Modern History Sourcebook: https://sourcebooks.fordham.edu/mod/iroquois.asp