The more interesting the better, but not offensive. Must understand the copyright law and be willing to ask permission to use other people's work. An eagle eye for proofreading can be recruited to help. Having a laser printer and scanner and E-Mail makes this job much easier. Extra genealogy software and expertise a plus.
Accuracy counts most here.
Must also be willing to enter extensive notes. Must make a clear distinction between known and documented ancestors and those who are connected to the family only by tradition. Must be willing to knock a U.S. president or a Mayflower Passenger off the family tree if the connection is not good enough. Have the goal of publishing the family book someday. Must respect the privacy of living relatives.