My friend Nick worked on this course with a friend of his who has sadly passed away, but he's made it available now for free in his memory. It includes a PDF guide plus two hours of supporting audio comprising seven easy lessons in how to identify what you know and competently teach it.
As Nick says, "we would love you to have access to Rick’s material free of charge – with just one condition – please use the material to teach what you have to share."
Might be of interest to all those "long-time learners, first-time teachers" out there?