What you want is:
Create fillable PDF formsThat is a feature of the Adobe product. But you wan to use a free product, namely Open Office.
Make PDF form in Openoffice 3.3
http://www.taming-openoffice-org.com/newsite/?cat=27Archive for the ‘PDF’ Category.
New book: Taming Apache OpenOffice
11 May 2013
Taming Apache OpenOfficeThis book is for anyone who wants to get up to speed quickly with Apache OpenOffice.org 3.4. It introduces Writer (word processing), Calc (spreadsheets), Impress (presentations), Draw (vector drawings), Math (equation editor) and Base (database), as well as common features including styles, templates, printing, a gallery of graphics, and macros.
...
Did you know you can send a final document as a PDF attachment that everyone will be able to open and view, but which people who need to will also be able to open and edit? The document that can do this magic is called a “Hybrid PDF”, and anyone can make one using open source software. LibreOffice (and related packages like OpenOffice.org) have been able to make these editable PDFs for quite some time. A Hybrid PDF is a normal PDF file that any PDF reader can display, but with the added benefit that the original source document is also embedded in the file. Any suitably advanced office suite, such as LibreOffice, is able to retrieve the source and allow you to edit it.
For more information, just download the Open Office documentation and read it.
