Open the site of the Google map, enter your address and search your map location.
After this click on the link icon button on the same page to get the iframe code of the map.
Copy the iframe code and place the code in the Home Page sidebar widget and save it.
Alternatively, you can place the same code in any of the footer widgets and save it.
Just in case if you want an alternative approach to implement the Google map on your website, I would recommend you to try Comprehensive Google Map Plugin (http://wordpress.org/plugins/comprehensive-google-map-plugin/) on your website.