Another website is for Chinese American Museum, http://www.camla.org/index.htm. It is very easy to navigate and main menus are on the side instead of on the top (if you are more used to the menu on the top).
One highlight is that on the website you will find one curriculum under "Education Program". The curriculum is about Lantern festival (but surely you can use it for holiday celebration units) designed for 1-6th graders.
Another very interesting link on this site, http://www.camla.org/history.htm, a brief history of Chinese American in Los Angeles, with links on the bottoms to three personal stories of Chinese immigrant families.
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