Hey, I actually did a presentation on Arc for a weekend gathering in Minneapolis. It may or may not present things the way you're thinking, but you're welcome to lift whatever you'd like, if it would be helpful:
It starts by just showing the same nuts and bolts stuff as PG's Arc tutorial, but then I elaborated on creating macros for creating objects and classes, which I thought would resonate with the target audience.
(Forgive the weird formatting; it's a Powerpoint export from Google Presentations.)
