Here is an overview of the map widget.
Here are step by step instructions on adding a map to your blog articles.
In your article editor click "Manage Media Items"
Click "Map" on the Choose a Media Item to Add dialog.
Click Add a New Location
Enter either the address of your new location or you can enter the Latitude and Longitude of your location. Click Add next to the method your used to enter the location information.
You will now be asked to confirm your address location. If the address is not exactly correct you can make adjustments after applying to new location.
You can not edit the Title and Description for your location. You can even change the map icon for the location. Click on the location marker on the map to bring up the properties for the location.
Remove the default location if this is a new map. To remove any location you will click on the locations marker then click "Remove" in the location editor.
Click the "Save" button in the upper right corner. This will return you to the article editor where you can place the map in your post.