Replying to Driving across the country for the first time

Later this week I am taking my dog across country from Massachusetts to Oregon to visit with friends and look for studio/housing space. This will be my first drive across country/driving more than 12 hours straight and i'm wondering if anyone has solid advice to help with my trip. How long should I drive a day? Where should I stop along the way? I am an oil painter and I enjoy photography and am looking to find motivation along the way. So anywhere that sparks your interest probably sparks mine, urban or rural.
What are your experiences driving across country?