In Google Earth, the yellow thumbtack tool is your 'placemark' tool you'll notice that when you click on that tool you get a yellow placemark icon in your window with an active boundary border around it. You can click the active placemark and drag it to where your building is, you will notice that as you do so, the recorded coordinates for your placemark change as well. Once your placemark is where you need it, you can click 'ok' in your active window and it will log the coordinates for that placemark.
You can do this as many times as needed and save additional location data as you save the various placemarks, for instance renaming them as building 1, building 2, etc. or whatever you need.
From there you can right click your 'My Places' layer in your table of contents and select the 'save place as' option. The default file type is a .kml file which is the primary GIS file type for Google Earth and can be imported into most other GIS software that I know of. The lat long data is preserved in the layer along with any unique naming convention that you assigned.
If importing into ArcMap however, you'll probably have to build new x,y fields in table view and calculate geometry to get the locations back into your attributes.
You can perform these same actions for the 'add polygon' tool and 'new path' tool for creating various layers. You can also download Google Earth Pro for free now which opens up additional functionality for importing/exporting various other GIS filetypes.
When you first download Google Earth Pro, you should see options for obtaining the licence and username, in a sense I think you end up linking it to your Google+ account or .gmail if you have one, or they walk you through creating one. Then they email you the licence keycode and you copy it over.
In order to automate your data, you could try importing a table into your 'my places' as long as the table has either addresses or lat/long for the buildings in it already. You go to 'file', 'open' and click the filetype drop down to all files, which will allow you to find a .txt file. You have a lot of options here, but I find that saving my spreadsheet to a .txt (tab deliminated) works well. From there, the import wizard in Google Earth will ask you which fields are your lat/long fields. If you have lat/long, simply tell Google Earth Pro which fields to look at. Once you've done that it should plot them for you.
If you have addresses instead, you check the box that says you don't have lat/long and it will take you to the addressing part of the wizard. From here, tell it if you have the entire address in one field or in multiples and plug in the necessary data. Again, when you complete the wizard it should plot it for you as best it can and then you can follow the process to export your 'my places' into a .kml
