Hi Zel,
Ahh, that makes sense. Well I think this is a two fold problem. The first is representing the document and the second is getting the signature.
So to represent the document you can either just include it in the survey as text in a question title, or provide a link to the document on your server (preferable one that opens in a new window).
To get the signature there are several methods depending on what level of identification you require. You can just include a single required checkbox, and all the person has to do is check the checkbox to proceed with the survey.
If you require a little more, you can also include a textbox that requires the person to type in their name.
If you require even more you can use our Survey Login feature. This will allow you to generate random one time use passwords that you can email to your survey takers and they will have to enter in to proceed with the survey. In this way you will know who used the password (by the email address you sent it to) and if they used them (they deactivate after use).
Hope this helps,
Chad