It is possible to delete a question before either a question goes to voting or a "Best Answer" is selected.

When a question is deleted, all the answers to the question are also deleted. While you cannot restore a deleted question, you can ask it again. No points are deducted for deleting a question.

1. Click on the Action Bar
2. Select Edit | Delete Question
   

It is not possible to edit a question once it has been submitted. This is to ensure that answers remain relevant to the original question.
However, it is possible to add details to an open question via the "Action Bar." To add details to a question:

1. Click on the Action Bar
2. Select Edit | Add Details