Try the skijoring email list or a club in your area. This is a great resource for discussing training, equipment, you name it.
Members can view an archive of previous messages at the group's website.
Mushing Magazine or Sled Dog Central . Their members may know what's going on with skijoring in your area. The closest thing is the International Federation of Sleddog Sports North American Subcommittee on Skijoring. Canada Manitoba Snow Motion Winter Dog Sports Club .