You could just get a guidebook, lonely planet or whatever.
They usually have maps, tips on places to visit, restaurants, ... and best of all work without internet connection.
I could, but considering the length of my road trip, I'd probably need nearly a dozen, if they're done by state (more if some cover only a portion of a state): My trip will cover:
Colorado->Kansas->Missouri->Arkansas->Alabama->Georgia->Florida->Mississippi->Louisiana->Texas->New Mexico->Colorado
I don't want a library of guide books to be taking up space in the trunk.
Guidebooks remain surprisingly useful for a lot of circumstances. They're far from perfect and tend to be out of date for food/lodging but they're still a well-organized and inexpensive resource that at least provides a solid starting point.
