Google Earth is an excellent tool for georeferencing - the process of adding co-ordinates to textual locality information. It can be used as a gazetteer (See the 'Fly to' search box), as a map (obviously!) and to measure distances e.g. '10 miles north of Nairobi' (see the 'Ruler' tool - Tools > Ruler). A less obvious, but still useful tool for georeferencing is the image overlay option. You could, for example, overlay an image of districts on to the Google Earth map to make sure your species is in the right place. At the present time Google Earth does have regional administration boundaries (make sure the Borders and Labels layer is ticked), but this is not consistent across the globe. You may find an image for your country with more detailed (and perhaps more accurate) information. A good place to find images of regions/districts for many countries is Wikipedia
Here's how to add the overlay using an example from Somalia:
1. Find an image of districts and save the file. See below for an example:
2. Open Google Earth and set the extent to approximately the same size as your districts image extent.
3. Add an Image Overlay (Add > Image Overlay...)
3. Browse to the file you saved and name your overlay
4. Use the green position markers to drag your image to the correct position (or as best you can) and click OK
The transparency slider is also really useful to adjust your image from clear to opaque.
Now you can check your localities to make sure they are in the right region.