Clear crisp pictures of piece overall, front and back. Close up of Details and any construction (any screws used to attach pieces together). Pictures of any signatures, unusual marks (not consistent with the decor on the piece).
And of course, history of how you came to be with the piece and what you know about it before you got it.
Natural daylight is best (less glare) If a light in color object is to be photographed put with a dark solid background (use a solid sheet or blanket) or if object is dark in color use a light solid color background.