First of all, hooray for free (as in speech and as in beer) software! That said, you might want to check out
LibreOffice: http://www.libreoffice.org/
I don't want to bore people with the technical details, licensing issues, and politics involved in LibreOffice vs. OpenOffice, but I think LibreOffice is now more widely used and supported. It might be a good idea to link to it as well on the main page.