I cannot overemphasize the importance of including sources when entering data in a
genealogical software system. Even if your research is perfect and you never come
across contradictory evidence, your research is a historical document and someone
in the future who may pick up your work will question "where did s/he get that
information?"

Another suggestion. If you have a scanner and are using genealogical software,
scan the documents (photos, etc.) and attach them to all persons impacted by the
record. In that way, if you have some reason to challenge a source (such as
contradictory evidence), you will not have to search for the document; it will be
readily available.

Gary Mokotoff