Once you have scored all of your chestnuts, stick them in a 375 degree oven for 10-15 minutes until they pop open, allow them to cool, and then pull open the shells. Store the chestnut meat in the fridge if you're going to use it in a few days. Or you can just keep 'em in the freezer for up to a month.
BTW, I bought these particular chestnuts at the Memphis Botanic Garden's Wednesday afternoon farmers market. They are from the garden's very own trees. Be on the lookout for chestnuts from the very same haul to be on menus around town this month! Today, I'm thinking of making some sort of chestnut cream...