Conducting an interview, coming up with good questions and establishing a report, is a challenging process. Transcribing that interview can also be difficult, and requires precise listening skills, patience, and careful editing. An hour-long interview can easily take 4 to 6 hours to transcribe, depending on how fast you type. Make sure you allow enough time to transcribe interviews accurately, and maintain the tone and quality of the original audio.
If you are transcribing an interview that someone else conducted, it's important to familiarize yourself with the subject's style and the context of the interview. Listen to at least a good portion of the interview first, before any typing, to prepare yourself.
When typing up the interview, to add clarity, you can add some clues to the tone of the interview in brackets, (e.g. [laughs], [points at bandmate]). Add these in either the first draft, or in the second edit when re-listening to the tape.
Words are harsher in print, so editing of filler and adding context afterwards can help present your subject in the correct light. Read over the final copy and make sure that your interview subject doesn't end up sounding more extreme or less articulate than they are in real life.
From my experience transcribing documentary interviews, I've found that you want to also we the specifications of the person that's hired you. A lot of times they want things exactly as they were said, including all the "ums" and "ahs."
If you're lucky enough to be using a digital file to transcribe from, there's plenty of software you can use to slow the file down so that you can type it up in real time (depending on how fast you type), which makes it easier.