Jill, I’m a german speaking InDesign and InCopy-Trainer. When I start long time ago with InDesign and InCopy, I found, that the InDesign AND the InCopy-Trainings at Lynda.com are very well done and especially the Incopy workflow is very well explained. I could understand everything, although it is not my mother tongue.
To your problem:
It sounds, that both of you have no good idea, how to start and it sounds, that you get icml-files instead of assignments.
So, some thoughts:
1. The designer work in InDesign.
2. The editor work with InCopy.
3. Both can work on the same network, but Dropbox and working from home will work too.
4. You and the designer need the same fonts. There is no real packacking!
5. You have the ability to change text, but no geometry.
6. The designer must start a workflow and give you the right for different stories. There are several ways to do this!
7. After that, you could edit the indesignfile or a so called assignment (e.g. some spreads instead of the whole document).
8. You should never edit the icml-files, since this shows only text and not the geometry.
9. Once the workflow has started, you must check out the stories. Otherwise it is not possible to edit something.
I did a presentation in 2013 for Adobe. The presentation is in german language, but it should work without any sound too ;-)
https://www.youtube.com/watch?v=sR–k7Oa2qw&t=28s
The InCopy-part starts at 41:15.
I would think, that a online-session (1 hour) could be helpful to him and then he should watch the lynda-training again.
Kai