If you need to add your signature to a PDF document you can do this by opening the PDF in Adobe Reader and click on the 'Fill & Sign' link
Then click on the 'Sign' button
Then select 'add signature' from the drop down menu
Type your signature name and click on the 'apply' button when done
Then place the signature block in the corrected location on the document page (1) and then click on the 'save' button (2)
Now when you open the document you will see the signature block which cannot be edited
