So, one of the many things that we discussed at yesterday's BALUG meeting ... ssh
Notably some bits about how to well and properly use it, getting used to it, folks getting stuff wrong ... and right.
Anway, thought of it bit later after meeting, but I do have materials on ssh which I've repeatedly used in helping train folks on ssh and security thereof, etc.
https://www.mpaoli.net/~michael/linux/ssh/ssh.odp Yes, presented before at BALUG and for other trainings/presentations. (hmmm, I should probably also add ssh certs to it, and some other modest updates).
Also, originals from the much earlier BALUG presentation: https://www.archive.balug.org/2010/2010-02-16/