Wandering through my local 1/2 Price Books I came across the The Art Of Teaching Craft: A Complete Handbook by Joyce Spencer and Deborah Kneen. Written in 1995 it is just what I'd been searching for to help me prepare for my calligraphy and illumination classes.
It is a practical guide to teaching small to medium classes, in your own home, your studio or at another venue. It details how to set up your space, plan your class, provide teaching aids and keep records. The authors also include multiple check-lists to summarize each section. I find it's very useful for lesson plans.
Written in 1995 for those living in Australia, it still applies to teaching crafts in the U.S. today. Although if you are starting a business you would want to confer with a lawyer on legal things.
An easy to read book and well thought out. However, I would love to see it updated. One that would include the use of internet media such as Pinterest, Facebook, eVite and Google Doc, Sheets, Slides and Forms. So much has changed in internet media that are useful for small group teaching, but may be unknown to some.