Questionnaire

[Mike]

How do I get a questionnaire form to appear during the checkout procedure?

[little-linguist]

Do you mean when customers sign up e.g. to ask a question such as "where did you find out about us etc.?"
If so, you first create the form in the form editor and then go to site-->configuration-->general options and then scroll to the "additional form" field (in the 4th "block" down). From that list, pick the new form you just created. The drop down menu below lets you decide how that data is used, e.g emailed to you each time someone signs up or it can be saved to their user account (or both!)

[Mike]

Thanks little-linguist but what I was meaning was a form when they are checking out during a purchase to ask where they found us etc.

Actually looking at what you've suggested above may do the trick as we would only need that info once.