Fly Fishing Only, a shop in Fairfield, Maine sponsors a two day school, but I think it has already taken place this year. LL Bean in Freeport, ME also offers them in the spring/summer. You might try Stone River Outfitters In NH, or check with your local TU or FFF chapter. The easiest thing to do might be to watch a video such as Introduction to Spey casting with John and Amy Hazel, or Spey to Z, among many others. Each of these videos details several types of Sakgit casts such as the Double Spey, Circle Spey, Snap T, and Snake Roll. (Spey to Z will also show you the Perry Poke). If you are reasonably adept with the one hander, you should be able to figure things out well enough from a video to get yourself on the water. At the very least, half the fun is in learning and practicing a new skill.