There are great resources out there to help project managers understand the philosophy of transcribing recordings of oral history interviews. But that's just one piece of the post-processing puzzle, as you are discovering.
For the Office of Historic Alexandria (Alexandria, Virginia), if our interviewee deletes or changes anything (most often deleted are many of the the "ums" and "yeah"s), we put the following on the bottom of the front page of the transcript:
This transcript has been edited by the interviewee and may not reflect the audio-recording exactly.
You can see what we have online at: http://www.alexandriava.gov/historic/info/default.aspx?id=29562
One thing I have told interviewees is that if they would like to add or delete material (more than a sentence or two), I need to note it in the transcript. For example, if someone told me a story that they later thought was irrelevant to the overall project, then I'll take it out with a note: [Excerpt deleted by request of the narrator.] When something is deleted, readers are naturally curious as to what was said.
For the interviewee? What are you trying to accomplish? We use the Baylor University Institute for Oral History guidelines, but transcribing oral histories is one of the most complicated things we do. A set of guidelines for narrators would be a GREAT IDEA!
Here are some of their cautions: A transcript represents in print the words and extraneous sounds present in the recorded interview. The transcriber’s goal is to render as close a replica to the actual event as possible.
I would like to hear from people who provide their interviewees with transcript editing guidelines. How has this worked in practice? Would you be willing to share your guidelines?