This is a great resource for anyone with a SmartBoard.
As you're reviewing responses to your form, keep in mind that you can't prevent users from submitting a form more than once, so the same person may have submitted multiple responses. If you use Google Apps, you can choose to record the email addresses of people who fill out your form and then easily identify any duplicate responses.
To close your form to new responses, click the Accepting Responses button in the toolbar to toggle responses off. The toolbar button will then say "Not accepting responses." If you’d like to re-open your form to responses again later, you can click this button again to toggle responses back on.
If a form is no longer accepting responses, visitors to the form will see a message letting them know their responses won’t be collected. To customize this message, change the text that appears under the heading "This form has been turned off," which appears near the top of your form.