KML is the native datafile format used by Google Earth. KML is a fairly complex XML format and it is not easy to simply create a KML file from scratch, especially if you are starting with a list of street addresses. It is far more simple to use an automated script to convert these addresses into a KML format which can be imported into Google Earth. From that point, you can add icons or use the map you have created in a presentation or to send to friends and family.
