There are often indices available that make it easier to locate someone. A more detailed discussion of courthouse records is at Cajun Genealogy in the 19th Century . Again, the books now cover smaller areas and time periods. The total number of Acadian descendants in Louisiana reaches tens of thousands and even hundreds of thousands. Check out the Book List page, though it is by no means complete.
Newspapers are good sources for obituaries, birth notices, and marriage information.
Some have had their information indexed, especially the obituaries. The best and easiest resource is often the older members of the family. They can often give information that will take you back to the 1800's.