If your family remained in the same district for a long time, as most Cornish families did, the parish records will be invaluable to your search. Baptisms, marriages and burials were registered in the parishes as early as 1538. Unfortunately, they were often kept on loose sheets of paper. In 1597, all parishes were ordered to keep the records in a book, so that they would not be lost for future generations.
The main Cornish website www.rootsweb.com/~engcornw/ is a good place to begin your Cornish ancestor search. One of the many features is a link to Cornwall parishes. As stated earlier, parishes will provide many of the keys that will unlock your ancestry. The parish page lists the 257 parishes located in Cornwall. A map is provided, so you will be able to pinpoint the location of your ancestors and get some idea of the geographic placement. It is good to know your ancestor's parish, as well as the surrounding parishes. If you click into the parishes, you will be given the name of an online parish clerk who may be able to help you with your research. This website is a work in progress. Parish records will provide more detailed information about your Cornish ancestors.
The Cornwall Online Census Project (COCP) is an excellent online resource, located at http://freepages.genealogy.rootsweb.com/~kayhin/cocp.html. Not all of the censuses for the different parishes in Cornwall are available, but the one you need may be there. This source may be used to locate census records from 1841 to the last records that may be viewed today.
Another good source for the United Kingdom censuses is located at http://freecen.rootsweb.com. Although not all of the records are loaded, you may be able to find your family. The free census is quite easy to use and provides some excellent data.
The John Berryman family in Cornwall is an interesting example of the importance of using the censuses on the web. Family history says that John Berryman came from St. Ives, Cornwall, to Ishpeming, Michigan. Knowing the parish in the beginning provides a greater opportunity to find the information. After going into freecen.rootsweb.com, the name, John Berryman, was entered. The only other lines filled out included marital status, where living, age within ten years and 1891 (for the 1891 census). Thirteen records were found in Cornwall. Since it was already known that John Berryman migrated from St. Ives, the search was narrowed even more. I went straight to my ancestor.
The webpage provided his sex, age, occupation and place of birth, as well as that for his wife and two daughters. Their relationship to John Berryman is stated, so that if a niece, nephew or other relative is living in the household, it is written. The Civil Parish, which was St. Ives, and the Ecclesiastical Parish, which was Halsetown, were also listed. Knowing these parishes provides an opportunity for more in-depth research on the families. It is important to remember that records in the civil and ecclesiastical parishes may provide different information. The address, Trelyon, is also given.
One interesting feature of the webpage is that at the bottom of the page, there is a place to click to view the previously listed household, as well as for the next household listed on the original census. Remember that these are the two households that are physically the closest in placement to your ancestor. A researcher may be fortunate enough to find another generation living right next door to the one ancestor that you know. At the very least, a person will probably find some relatives.
Researching in Cornwall requires some patience, especially regarding the common surnames. Once a researcher has narrowed down the correct parish, the information will be found much more quickly and often in an amazing quantity.