Setting up Standard Lists allows to send surveys to contacts and leads. It is essential to complete this step to send surveys from Standard Lists. Once it's configured, you'll be able to choose contact/leads and also send surveys directly from the details page of the contacts/leads. 

View the tutorial to send leads by clicking here. Don't forget to set up Sites if you want to send surveys to people outside your Org.

If you are using a version previous to 3.71 please click here