You can add interactive form fields to a PDF by using the extensive form tools in Adobe LiveCycle Designer (Windows) or the basic form tools in Acrobat Professional.
Adobe LiveCycle Designer is a standalone application that is included with Adobe Acrobat Professional for Windows or can be purchased separately.
In Windows, you can initiate the process of creating a LiveCycle Designer form either from within that application or from Acrobat, using the Create New Forms wizard.
In Acrobat, you can initiate the process of creating an Acrobat form by clicking either Convert An Existing Document or Scan A Paper Form in the Getting Started window, or by opening an existing PDF and choosing Forms > Run Form Field Recognition.