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

Coaching

With just one room available these days, I have offered group coaching
sessions only during the Summer when no matches or individual
competitions will be going on.

This year, as usual, we discussed a series of topics suggested by
members, including an Opening Workshop, Creating and Exchanging strong
pieces, Making and Meeting Threats, and Endgame Elements. New material
on the London System, Caro-Kann and Budapest Gambit was posted on the
website.