Problems w/ Google Maps
I recently finished a tour of much of the midwest and used Google Maps with the 'bike route' option. This worked very well for some routes but on others I was led on loops. In IL I was dirested up a road for about a mile, left 1 mile, bear to the left for about a mile, then left to an intersection. I found myself right where I had started.
Also, Google led me down many gravel roads and some unpaved roads (just ruts). This was not an option for me with skinny road tires.
Just be aware that Google is good but not the answer to everything.
Great biking to you,