If you don’t know what Google Earth is, here is a brief synopsis:
Google Earth is a free-of-charge, downloadable virtual globe program. It maps the entire earth by pasting images obtained from satellite imagery, aerial photography and GIS over a 3D globe.
The satellite pictures of Madrid, though not as perfect as a city like New York, are still superb and allow you to clearly make out buildings,streets and parks. The Retiro Park and Royal Palace are clearly visible and you can even overlay roads to see the main streets of the city. It is not a bad tool to use if you plan to do some walks around the city and over time I’m sure the quality of images will get even better. There is another satellite mapping service for the Madrid region called Geomadrid but I don’t believe the quality of the images and its presentation is as good.
In order to use the software you will need to download it on to your desktop.