Transcribe written comments from paper surveys

We have run a survey with hundreds of paper questionnaires and now need to transcribe the open-ended free text comments into a spreadsheet.
The questionnaires have been scanned, so it's a matter of looking at the scanned image, and then copying the text as it stands into a spreadsheet we provide.
English is not the first language for most of the survey respondents so some work may need to be done in cleaning the comments up before transcribing them. For example, you should correct obvious spelling mistakes and correct the grammar where appropriate.
You should work accurately, have good attention to detail, and work at a decent pace.