I started coaching adults at the Exeter club in 1993, about the same time as Alan Maynard started up the current incarnation of Exeter Junior Chess Club. I went looking for some useful resources for teaching, and there were some, but mostly I became a magpie, picking shiny bits out of various good books. I did find it irksome that so many books repeated familiar examples, and I thought I could at least pull those out for my colleagues, and that became the core of the Canon. I found particularly useful:
* Tony Gillam - Simple Chess Tactics and Simple Checkmates