Apparently the second Ice Age is coming. Weather lore has it that when acorns cover the ground in October, snow will cover the land by Christmas. At the Urbane Forager, we say that you know it is autumn (even if you are still wearing shorts), when you can smell roasting chestnuts.
Peel off the burnt shells (let them cool a tad first), remove any pith you can get at and there you have it/them. The Head Chef insists on adding salt at this point but personally I think they taste fine as nature intened, only cooked.
Some people do eat sweet chestnuts raw but I don't.