Follow the steps below to create your API key.<br />
1. Go to https://code.google.com/apis/console/ ;<br />
2. On the Services Tab, enable the Google Maps API v3 option;<br />
3. On the API Access Tab, take note of the API key in the Simple API Access option;<br />
4. You can limit this API to specific domains by informing them in the 'Create new Browser key...' option;<br />
5. After save your API key on your site manager interface, you can track your API usage on the Reports tab.