I'm thinking about touring this summer and riding across Maryland. What is the best source for obtaining maps that will show bike friendly roads? At this point I am thinking about riding my road bike which is a Trek Apex H2. I plan on traveling very light and lodging at this point might be hotels. If I want to go the camp route then I would switch bikes to the Gary Fisher Tassajara with non-knobby tires. Any assistance in where to look for maps would be greatly appreciated.

Thanks
Mike