Plan the detail of the survey, and ensure that sufficient resources and people are available to perform it. This includes designing and distributing questionnaires, conducting interviews and collating and analyzing results.
Be aware of the time that will be required. For example, a phone survey may require two to three weeks, whilst a mail survey is likely to take at least two months before all responses are returned and collated.
Where appropriate, get permission to conduct the survey, indicating the expected start time and duration required. Also find out if the people have been recently surveyed on other topics as an otherwise helpful person could turn out to be irritated by 'yet more questions'.