If you want to learn about wild foods and you live around Bristol, check out www.gourmetfungi.co.uk (edit: link doesn’t work anymore) they offer various courses. They also sell wild food, including a wild food veg box, which defeats a main point of wild food (as the famous book says “Food for Free”), but hey, if you want nutritious food but don’t have time to collect it yourself, it might be for you!