AppleInsider on how to batch rename files in the Apple Finder
You learn something new every day, I didn’t actually realize that this was now built into the Mac OS, as I have always used A Better Finder Rename (and awesome app with more power than this, but it costs $22.95 unlike this tip but if you do check it out also check out A Better Finder Attribute it’s companion app).
So check out this article by Macolm Owen at AppleInsider.
Every editor will need to batch rename files at some point, and the fact that it is so easy to do in the finder now is an amazing thing.