A brief guide to modern evidence-based teaching methods aimed at people working with grassroots get-into-tech groups, based on the Software Carpentry instructor training course.
Chances are, you haven't heard of Software and Data Carpentry, two currently-merging nonprofit volunteer organisations that organise the open source creation of programming learning material, and organise 2/3-day workshops to teach programming and data management skills to beginners. I'm a certified instructor myself and have run quite a few workshops by now.
If you want to teach with the organisation you have to undergo a Train the Trainers workshop which is all about the psychology of teaching & learning. Greg Wilson founded Software Carpentry and wrote this little helpful book summarising the very recent research, essentially a Train the Trainers workshop in book form. The focus is clearly on programming workshops, but other 'hands-on' teachers should benefit too. There's stuff about how to motivate and how to accidentally demotivate (say 'you'll just have to...' to imply that the asker is stupid), benefits of a Code of Conduct, benefits of live coding, how does memory work and what role does repetition play, imposter syndrome, etc. pp. It's all very much geared at the structure of Software Carpentry workshops but the lessons are applicable to any (programming) class.
If you've been following Wilson on The book is available online for free here, but you can also buy a physical copy here.