You should cite every source that you use in your research. If two sources contain conflicting information, you should still cite both. You will have to make a judgment call as to which information is the best, but you should record the differing information too.
Citing every source you use does not mean that you have to use every source you come across. If you have good evidence that a particular writer or compiler consistently puts out false or mistaken data, you can legitimately ignore that source. You might, however, want to make a note about why you believe the information to be incorrect so that other researchers can be warned.Great genealogy research is not just copying what you find in other works. To really do good research you must consciously evaluate every piece of information you come across and make informed decisions as to which bits of data are best. When doing family history research, we are dealing with dates, places and names that were recorded by fallible humans. We can never be 100% sure our conclusions are precisely correct. Still, we must make every effort to adhere to strict standards for good research and quality of proof to keep those errors to a minimum.
To document your sources properly, you will have to learn a little about the mechanics of source citation. Cyndi’s List
has links to several resources you can find online. Good t
ools you can use to help create the actual citations are Landmark’s Citation Machine
. Certainly the most used reference for genealogical citation is Evidence! Citation & Analysis for the Family Historian
by Elizabeth Shown Mills. Ms. Mills is widely considered to be THE authority on documentation for family history research.