Digital documents sometimes need signatures. You can print it out and mail a hard copy for a signature, fax it, or scan it and email (and hope they figure out how to sign it and get it back to you in some form).
If you want to streamline your document signature process, now you can if you use Adobe Acrobat. Yes, we pay for the software. It's worth it because we have to sign (and get signatures on) a lot of documents. It may be worth it for you too. For fast help you can ask the new Electronic Signature Guide at Adobe:
Other good news: You can now edit a PDF file. If you've tried to do this in the past, well, I feel your pain. Now, even if you only use the free version of Adobe Reader, you can edit. Yippee!
If you want to edit a PDF, go here. Whether you need to edit a word or sentence, an image, a few pages, scanned pages, or an entire document, this guide will give you info on how to. Of course, the paid versions give you lots more options and control over your document, but the free version will give you a place to start and see some of the possibilities without any financial commitment.
If you want to get the free version of Adobe Reader, go here.