Been a long time since I looked, but Evergreen Safety Council (?) is the popular one. Seems like there is another group around, too. Do a search for MSF or Motorcycle Safety Foundation/Seattle and you should hit gold.
Totally worth your money, too. Any training is, actually.
Any moto shop should have brochures or sign-up info.
If I had a surplus of spare time, I would jump on being a MSF instructor! I enjoy teaching people things and that would be a great way to spend some retirement time (in about 30 years...).