While browsing for a legal replacement for Adobe Acrobat’s expensive PDF creation tools on Windows, I found several interesting links about this proprietary format (although its specs are public).
Although you can install OpenOffice.org which includes automatic PDF generation, sometimes that’s overkill. Maybe you only have MS Office, in which case this article about converting documents Microsoft Word to PDF may be enough.
I found PDFCreator to be much more similar to the original PDF printer drivers that were very cheap. Of course it’s not a full featured editing tool but I find it to be the next best thing.