Another tool worth checking out for making a map from a spreadsheet is GeoSheets (http://www.geosheets.com). It makes it easy to do lightweight GIS tasks like geocoding a bunch of addresses and making a custom map. It's an add-on for Google Spreadsheets, so usage is as simple as listing some locations (addresses, lat/lng's, whatever) in your spreadsheet and typing =GEO_MAP(A1:A10,"map").