Nutrition on the road - What, How and Why?

Best thing I can advise is that in the three or four days leading up to the ride is to eat normally, drink a reasonable amount of fluids and avoid things that will dehydrate you such as getting pissed...
...or drinking loads of coffee. If you need a caffeine kick to keep you going, try to save it up for towards the end of the ride, so you really feel the benefits of it hitting your bloodstream in the wee (sorry) small hours.