The Automobile Club of America is a great resource for planning trips as are a number of map-oriented Internet sites such as mapquest.com, mapsonus.com, maps.com, mapblast.com, topozone.com 
and randmcnally.com.  These sites not only provide maps and door-to-door driving instructions, they allow these instructions to be tailored based upon how long you want to be one the road, whether you are traveling with children and/or pets and what sorts of entertainment or activities you might be interested.  Some of the sites allow for the making of hotel reservations; the locating of restaurants, shops, gas stations and ATMs and; providing real-time traffic updates.

Global Positioning Systems that are installed in your car show, and in some cases tell, you how to get from point to point and how to detour around traffic jams.