How to manually edit locations in iPhoto 9.5 ('11) in a bigger window?
I also miss Google Maps in the newer iPhoto, so I use Picasa (which uses Google Maps) to add location data and keywords to the image files before importing them into iPhoto. Using Picasa for this is easier and has the added benefit that if I export them later as "originals" they have the location and keyword data embedded in the exif part of the file. When you add location and keywords to photos (or even change the name) in iPhoto, it stores the info in a database, not in the image file. I work only with JPEGs, so I don't know how Picasa handles RAW files.

Here's my process using standard apps already on my Mac (Mavericks) and Picasa 3.9 (free download):


Use Image Capture to import photos to a folder on my desktop
Use Automator to rename the images with the date and time, for example IMG-2014-01-02-143612. By including the time down to the second, every image has a unique name which will sort chronologically. This might also be a good time to add something descriptive to a group of photo titles, like IMG-2014-01-02-143612-Mount Everest :-)
Open folder in Picasa 3.9 to add location and keywords. Picasa will write this information to the exif part of the file and won't touch the actual image data.
Import images to iPhoto which will make use of the location data and keywords added in Picasa. If you export an "original" from iPhoto later, your location and keywords will be intact.