A fellow IT Redditor, /u/shalafi71, created quite a security training slideshow and generously shared his PowerPoint on /r/sysadmin, who also adds:
Take this as a skeleton and flesh it out on your own. Take an hour or two and research the things I talk about. Tailor this to your own environment and users. Make it relevant to your people. Include corporate stories, include your audience, exclude yourself.
This ain’t about how smart you are at infosec, and I can’t stress this enough, talk about how people can defendthemselves. Give them things to look for and action they can take. No one gives a shit about your firewall rules.
You can also check the slideshow directly here.