A brief visit last evening to my local ginkgo trees told me that the season of ginkgo nuts has passed. While I don’t have any first-hand knowledge this year, in the past I have seen small groups of middle-aged Korean women collecting the nuts.
Dover describes her own autumn ginkgo nut-gathering expedition. She also links to a page that describes the ginkgo nut roasting process. When I first visited the page, there were instructions (albeit in Japanese), but the pictures are descriptive.