Getting a work appraised: the family David de Noter

Kitchen Interior, 1845, Oil on panel

Rather like the current exhibition at the Hermitage (thank you Google Art Project), my family has a de Noter on view-- at home in our living room. It's a charming scene with an elegant woman in a yellow dress feeding a spaniel a treat. Its been hanging there for just about forever, or at least since we inherited it from my great-Aunt Charm in Atlanta.

Woman peeling an orange

David Emile Jospeh de Noter was a Belgan painter in the 1800s who did still lives and interior domestic scenes, and there are some examples still lives up his up for auction currently at Sotheby's and Christies. Apparently he was quite prolific and remains popular; a quick Google search will give you many opportunities to buy posters of his works.

I'd be interested both in learning the value of the painting, especially for insurance purposes. How does one go about having such a work appraised? Do we just take photos and email them to someone at an auction house?