OpenStreetMap is a free resource that is getting better all the time

[PeterC]

OpenStreetMap has many contributors, and many tools that use its data and products. In many places it has limited information, but the option is there to add our own. You can see the map itself here.

There is a basic eBook on OpenStreetMap at http://en.flossmanuals.net/openstreetmap/, covering such items as My first edit; Collecting data; Sharing your maps; Editing the map; Providing maps for your web site. One very useful page is on Understanding the OpenStreetMap data model.

LearnOSM enables you to "Learn OpenStreetMap Step by Step", and the OpenStreetMap 101 blog at MapBox is a good introduction to OSM.

OpenLevelUp enables you to see indoor data from the OpenStreetMap project.

Mapbox work closely with OpenStreetMap, and their blog article Get on OpenStreetMap! is a guide to getting started with editing OpenStreetMap.

This article answers the question Why would you use OpenStreetMap if there is Google Maps?

Where is OpenStreetMap in 2017?