I have a large number of parcels (closed polylines) all with object data attached to them.  I'm trying to label all of the parcels with one of the fields of their object data.  Is there a way to select these parcels, select which field I would like to have displayed and have this task performed automatically?

Not with plain AutoCAD, but since you have parcels & object data you are probably using something like AutoCAD Map? I don't use it, but expect you can do that in Map...