Move your cursor to where you want to place the block and click With Adobe Acrobat or Adobe Acrobat Reader, you can easily use the Fill & Sign tool to complete and send your forms or documents electronically. Adobe Document Cloud. Get PDFs signed by others using Adobe Sign Follow the steps below to add a signature block to PDF documents: Open the PDF with Adobe Acrobat. Add an electronic signature to a PDF document online in a few easy steps In the Forms & Signature sections, choose Prepare Form