It would be great to have a one hour session on each of the report categories. Start with the same subset of data and show what each report looks like for that particular data. For example, start with the Contact report type and show what each of those 8 reports looks like all using the same data.
Tips on modifying layout and sorting options would be great as well. I think that periodic report training would be good to offer.
I would take many notes at this one.