Among the best detailing advice around can be found in the detailing e-book by DavidB (downloadable free from this site)
As for a duster-
The best known brand (California Car Duster) it can be used to remove pollen or light dust without causing scratches by applying very little surface pressure with the duster, dusting with long strokes in one direction only. Shake the duster occasionally to ensure any particles picked up will drop out rather than come to the surface while your using it.
It important to use the duster only for the removal of dry surface dust, if the vehicle has oily road film, road tar, damp pollen or dust, etc the vehicle surface should be washed
When the duster is first purchased it should be wrapped in newspaper to remove any excess paraffin wax, the duster should not be washed, the dirtier it gets the better it works (I've been using mine now for almost five years without it being washed)
JonM