How should I prepare?

Ride your bike a lot.
The more you ride, the better shape you'll be in.
Get comfortable riding longer distances.
Each day on the route is between 30 and 40 miles, but because of the climbing and rough roads it seems a lot longer.
Get comfortable riding gravel roads.
It takes some practice navigating loose gravel or rocky roads. Best to develop the skills before the tour.
Get comfortable camping.
You'll be tired from the ride when you get to camp. You'll want to know you can setup your tent without having to think about it too much.
Have your bike serviced.
You'll want the assurance that your bile is in good shape and won't start falling apart when we hit the bumpy roads.