Determine where you want to go, and whether or not you want to take a direct route, or a scenic route. There are advantages to both but, if time is not of the essence, it will be more adventurous and richly rewarding of a trip if you stay off the main four-lane highways.
Buy a map of the state where you will be traveling, and be sure that the map includes blown-up street-level images of the major cities through which you'll be passing.
Use the map index to find the town or towns you wish to travel to. The index is arranged alphabetically, so the towns are easy to find. Next to the town name, you will see a series of letters or numbers, or both, which indicate the location of the town according to the overlying grid formation which you'll note on the map.
Plot your course, by paying attention to the directness of the route, as well as to the presence of any places of historical importance along the way. Read the "legend" on the map to see which types of roads are four-laners, and which are roads built for lesser speed.
Calculate the miles that you'll need to travel; a road map normally includes miles from point to point along the roadways, so it's easy to see your projected distance to your destination. Take into account the quality of the roads along the way, as well. You'll make better time on a four-lane road than you will on a road that goes through many small towns.