Yes, rename sounds like exactly the tool for the job, very simple and quick. But several answers in that "dear god look at these examples" StackOverflow thread do use rename (sometimes embedded in find commands or other), so I'm not sure what OP is looking for.

  rename 's/foo/bar/g' *

seems pretty unbeatable. If you need to choose the files more elaborately, combine it with find (I prefer xargs to -exec):

  find . -name '*.txt' -print0 | xargs -0 rename 's/foo/bar/g'

-print0 and -0 use null separators so can handle filenames with spaces etc.