1900-1930 Census--The Family History Library has the U.S. federal censuses of Hawaii for 1900, 1910, 1920, and 1930.
Soundex--Soundex or phonetic indexes are available for the 1900, 1920, and 1930 censuses. The 1910 Federal Census has been published (FHL book 996.9 X22h 1910).
Ancestry--All census records for Hawaii have been indexed at Ancestry.
Colonial censuses exist for some portions of Hawaii for 1866, 1878, 1890, and 1896. The 1878 census is for Hilo only, and the 1896 is for the island of Oahu only. The 1890 and 1896 censuses are the most complete. They give the name, age, sex, and birthplace of every person. The 1878, 1890, and 1896 censuses are available at the Hawaii State Archives and the Family History Library (FHL films 1010681-88).
The Hawaii State Archives also has two "census files," 1840 to 1866 and 1847 to 1866, which contain miscellaneous records such as school census, population lists, and vital record summaries (FHL film 1009896 item 1-2 has records for 1840-1866).
Heritage Quest Online: http://www.heritagequestonline.com
Census Online: http://www.census-online.com/links/HI/
Genealogy Today: http://dir.genealogytoday.com/usa/hi/census.html
Access Genealogy: http://www.accessgenealogy.com/census/hawaii.htm
Hawaii Research Outline. Salt Lake City, Utah: Intellectual Reserve, Inc. Family History Department, 1998, 2001.