I can recommend A Guide to Introductory Physics Teaching by Arnold B. Arons (or maybe Teaching Introductory Physics which seems to be in practice a second edition of the former although I have not read it). I read it more than ten years ago and don't remember much more than that I found it a good book. It is centred on high-school level physics but has some contents also to related subjects, e.g. on how to show the students how to think on why they/we believe what they/we believe we do understand.