The number of Scandinavian folk music, dance, and cultural resources is large and growing. It is only possible to touch on some of the highlights here -- my apologies for any glaring omissions.
This list is starting small but will expand. Please contact me if you notice any errors or would like to suggest additional links.
Many of these websites are broad in their coverage. Some are focused on particular instruments, others are regional in nature, many performing groups both in the US and abroad have sites, and of course there are other tune archives.