Can I include a space for them to electronically sign a form?

I am trying to do an online contract but I need them to be able to electronically sign how do I do that?

If I understood you correctly, you want to allow your users to sign your form. You can achieve that by adding signature fields to your form. I would suggest you to use Smooth Signature or E-Signature. Inside of this guide you can find how to add a widget to your form: 

http://www.jotform.com/help/252-How-to-Add-a-Widget-to-your-Form 

Hope this will help. Let us know if you need further assistance.