You need to set a mapping provider—that is a service that will provide you with the visual maps—and a geocoding provider, which will translate your contact addresses into latitude and longitude coordinates.

Geocoding Provider finds latitude and longitude coordinates for each contact address. Mapping Provider uses this information to draw a local map, with a pointer for the contact. Geocode and Parse Addresses do the geocoding work each day, though you can change this in the settings.

Google currently limits geocoding requests to 2,500 per 24 hours. So, if you exceed this limit, Google may not process requests; it may even restrict access to their geocoding service should you continue to break this limit. This is a problem when you have thousands of addresses to process—for example, after a big import of address data.

CiviCRM does not have a tool to place a daily limit on the number of contacts that are processed each day. But you can put parameters into the Geocode and Parse Addresses scheduled job that provide a range of contact IDs to process. You would have to change this each day to work your way though all your contacts.