The document controller generates html containers for the other two and associates their controllers with their <div>s. I am, so far, treating each segment of the browser window as a separate page. That feels pretty close to right to me.
The category controller has a built-in init function that runs an ajax call to the C# Model to collect it's clickable listing.
When a click is made on a category, it publishes a Get.The.Details event and updates the user interface. The detail controller senses that (I love that JMVC has made that completely invisible to me) and issues another ajax call to get the details.
The only thing that's been really difficult so far is Scope. I did find "this.view()" in the video as Justin suggested, but it turns out that callbacks often don't have a good Scope and, until I learn something new, that's going to be a source of hassle and less generalized code than I want.
Here are two things that solved problems for me:
Getting the DOM element when it wasn't part of the scope:
Getting the current object when it wasn't coming through well:this.element.html(html);
Honestly, I don't understand it, but, it appears that Scope is going to be my bete noir for the time being. I suffer from it in C#, too.
Lots to learn but, it's been a good day.