You can't download the full versions, but you can download trials from www.microsoft.com. If you want a free office suite you can download openoffice.org which can read microsoft office documents too. http://www.openoffice.org, hope that helps!
You cant download it, you have to buy it. Its about £145 pounds for the entire Microsoft Office. You can however download OpenOffice for now, thats free and can be found here.