Chinatownology has a nice site on Chinatowns around the world: http://www.chinatownology.com/chinatowns_of_the_world.html, the following are those not included in their websites:
North America:
South America:
Europe:
Asia:
Library of Congress
National Archive
UC Berkely: Chinese American Archive
California Digital Library: Asian American
Ancestors in the Americas: Chinese American History Timeline
USC Digital Library: Chinese Historical Society
Ohio University: Overseas Chinese Databases
Thes following are selected resources from University of British Columbia Library's page on Asian Canadian Studies: