To add a signature to your Agreement report, add signature attachment to your party record.
To create a signature, use Microsoft Paint.
File | Image Properties. Set the dimensions to 250 width by 75 height (in Pixels)
Use the Pencil tool to draw your signature
Save the file as a PNG
To upload the signature, open your Party record (or whatever contact will be signing).
Click the Attachments tab
Upload your signature file
Set the Tag to "Signature Image". Make sure you only upload one of these files per Party record.
Now, when you set the Buyer Contact or Seller Contact on agreements, these signatures will be used.