Google Maps allows users to add content that's relevant to them on a map. It allows users to create personalized maps to overlay information such as photos, weather, and public transit maps.

To find content that you can add to Google Maps, open Google Maps(you need to login via a Google Account) then Click on My Maps and then Click on Add content. You will be shown a directory of content created by Google and by third-party developers:
Click on the title or thumbnail to get more information
When you find something that you're interested in, click on the Add it to Maps button.When you're finished, click on the Back to Google Maps link in the top left corner of the directory. Everything you just added will appear in the Created by others section of My Maps.

To display content that you've previously added to Google Maps:
Click on My Maps. You can show or hide a content layer by clicking on the check box next to its title. Information will then be displayed in the bottom pane of the left panel and/or on the map. In some cases, you will be asked to enter additional information in the bottom pane. You can display more than one layer at a time. Click on the title links in the top pane to switch between currently active layers.

To watch the Youtube tutorial click here.

Source:Google Maps