I have seen the distances vary from as little as 20 miles, up to 100 miles of biking. Be prepared for long distances, and get use to riding with a pack on. You should be able to go over rocks or other obstacles at any speed.

• Prepare your tool kit for flats. Practice changing flat tires. Check out Quick fills vs. small hand pumps. 
• Try to make your bike and gear as light weight as possible.
  
• Try different tires. Sometimes you can get by with those hybrid tires, and they save you in rolling resistance. Over a long distance, the rolling resistance of your tires make a difference.
• Look for ways to make your food and water accesible at all times. This is order to reduce stops. Constant movement forward is the name of the game.
• The team navigator should have the map situated on the handle bars. You are travelling faster, and need to keep an eye on the map. Also try to keep your compass visible.
• Lights are important! You will be riding at night on trails and roads. Practice this and experiment with different lighting systems. Some lights are brighter, but won't last the night.
• Experiment with towing systems. If you have a weak rider on your team, you can supplement their progress with the use of a bungee. Careful, this takes practice.
• Make sure your team has one toolkit that can handle most field repairs. Things like bent wheels or derailers can happen during a crash. be prepared for it. Know how to straighten a wheel enough to get by.