From a report by Jeff Legwold at the Denver Post, it sounds like the Broncos will be moving forward with many of their offensive assistants from the Josh McDaniels era. As expected, Legwold reports that Mike McCoy will be retained as offensive coordinator. He has a strong history with John Fox, having spent seven seasons as the quarterbacks coach in Carolina. McCoy took over as the Broncos' offensive coordinator when Josh McDaniels was fired.
Legwold also says that the Broncos will retain interim head coach Eric Studesville in some capacity, and my guess is he will stick as the running backs coach. Still, there have been reports all over that Carolina running backs coach Jim Skipper will also join the Broncos in some capacity. He has stated that he has indeed been contacted by Fox, but he doesn't know what his role will be. If I could speculate, I would say Skipper could come over as the running game coordinator, or something of the sort, and possibly an assistant head coaching position.
Legwold's report also indicated that wide receivers coach Adam Gase will also stick with Denver, and likely will transition from the wide receivers coach to the quarterbacks coach, opening the door for Tyke Tolbert to come over from Carolina to take the receiver position.
Still unknown is who will comprise Fox's defensive staff.