Maps

Maps are essential to hitchhiking. Make sure you always have a good map with you, the scale should at least be 1:700.000. In many countries it is very important to have a map that shows gas stations, service areas, toll gates and other important places on the motorways.

Paper maps

Europe

For Western, Northern and Southern Europe: one specific edition of the Marco Polo car map of Europe is great, it doesn't contain too much useless stuff like indices or city maps, and shows gas stations on highways! Unfortunately guaka^{site, wikitalk} only found this one in Slovakia.

"Philip's compact atlas Europe" shows service stations in some countries, is pretty compact and can be had for 7 euros at the New English Book Store in Amsterdam.

Online maps

For many countries in the world, there are very good maps at Google. You can also use Liftershalte.info, which is basically the same, except that it shows hitchhiking places.

For South America you can use map24.