This is actually “old” news but at a recent georeferencing workshop we gave, I was in the awkward position of having an outdated slide! As posted here under the Map Tools tab, we recommend Google Maps as an efficient and easy georeferencing tool to affix coordinates to a site. Further, we used to suggest third-party mapplets to enhance these tasks. My favorites were: Lat/Long Tool, and just for fun, Dig a Hole Through Earth. I used the former a lot since you can create a nice long list of coordinates in any format you need (DMS, DD, etc) then copy/paste them all into a spreadsheet of your localities. However, Google decided to deprecate the whole program of independent developers adding in Google Maps functionality and instead shove them onto little websites of their own.