|Percentage of Chinese population in the United States, 2000.|
The place to begin is with the FamilySearch.org Research Wiki article on China. FamilySearch is in the process of acquiring and digitizing Chinese records. As explained on the "China, Collection of Genealogies" article in the Research Wiki:
This collection will include records from 1239-2014.
The Chinese Genealogy Collection includes images acquired from various archives and libraries in China, Japan, Hong Kong, Taiwan, other areas in Southeast Asia and the United States.
The records are mostly about families who have lived in various provinces in China for several generations. They consist of clan genealogies, civil records, compiled biographies, histories and genealogy charts. Although some genealogies reach as far back as 1239, the time period and content of the records will vary from one genealogy to the next.
The size, generational depth, and type of information included in clan genealogies are varied. Some of the records that have been obtained from private households and collectors in Taiwan, Hong Kong, Southeast Asia, and the United States are hand-copied, single volume manuscripts, and only contain information about the most recent few generations or just a few pages of pedigree charts, while others are published records in standard format. Most of the records are easily readable, although some documents have been damaged due to aging, water droplets, and tight bindings. Since most of the records are written in traditional Chinese characters, it is assumed that the user should be able to read Chinese or get help from someone who can read Chinese to fully benefit from this collection. See the section titled For Help Reading These Records for translation tools.The FamilySearch.org Research Wiki is also available in Chinese:
Chinese Immigration and the Chinese in the United States (National Archives)
The Chinese in California 1850-1925 (Library of Congress)
Chinese Roots Wiki
How to Start Your Chinese Family Heritage Research
List of common Chinese surnames
Chinese Genealogy Resources (Historical Society of Pennsylvania)
There are many more resources available on the Internet. I suggest a search for "beginning Chinese genealogy."