Quite a number of books on processing give examples of the effect of varying exposure and development. If you can find an old copy of "Basic Photography" by Michael Langford, there is an excellent two page spread showing the same scene six times: three to illustrate the effect of exposure alone, and three to show the effect of development. Both accompanied by the film's characteristic curve, annotated. This is in the 1974 edition. The current edition has dropped this, and dropped in value as a result in my view.
Let me know if you are interested enough to want further details on the book, or a scan of the pages.