There are plenty of free software programs that you can type documents on. If you just intend printing them out, even Notepad is good enough - this should be on your pc as a standard part of Windows.
If you intend emailing your documents for others to read, OpenOffice is compatible with Word, and is free.
Have a look at Google Docs - this is a word processor that stores your documents online, so you can access them from any pc and share them with other people, if you wish.
https://www.google.com/accounts/ServiceLogin?service=writely&passive=true&nui=1&continue=
http://docs.google.com/&followup=http://docs.g oogle.com/<mpl=homepage&rm=false
http://www.openoffice.org/
Otherwise you will need to be Office - not cheap.