Indysteel, are you wanting to stay and visit cities only or get to little farms and countryside? If you are going to stay in the cities, definitely TAKE THE TRAIN!
If you decide you need a day in the country, the best thing to do is to take the train to a smaller town and rent a car from there.
But the best advice is to take the train and not drive. Trains are more convenient and a whole, whole, whole lot cheaper than renting a car. Renting a car is expensive because of the rental fees and tarifs (high), gas (like $8 gallon), tolls (very high--like $20 each time last time I was there), and parking (expensive and a total PITA).
So why would you want to drive, again??