If your need to look up a map your first destination might be Google Maps. However, Google Maps is useful only for reference but not for commercial use. Any company offering mapping services charges a fee for commercial use of information. However, OpenStreetMap saves the day. It’s a open mapping service which can be edited like a wiki. It provides data just like Google Maps. Also, unlike Google Maps it provides data under a creative commons license.
You don’t have to worry about if the Map is just made up like some entries in Wikipedia. Data is collected from various GPS devices when someone who would like to contribut to OSM takes on road. This way a genuine Map is produced. If roads are changed the map can be edited by registered users. Here is a simple how to contribute guide available.
Check out OpenStreetMaps and start contributing in your free rime. This is a kind of social service. So, don’t shy away.