I'm using Microsoft Word 2008 for Mac.

My problem is that I'm trying to Save to PDF but
the last letters on the right hand side are cut off.
I get a warning in MS Word prior to saving that states:

"A header of section 1 is outside the printable area of the page."

If I understand correctly, there's nothing I can do to expand the
printable area of the page for MS Word. So I thought if I saved
it as a PDF that might make a diff but it does not. When I look
at it in the Print Preview everything looks fine. Its not close to
the edge of the paper at all. I tried to adjust margins but that
doesn't work either. How can I resolve this problem? I don't
want to have to reformat the whole word doc.

I have to submit some writings in PDF format so this is why
it's important to Save to PDF, but it seems the problem is
with printing in general. Please Help.

It's possible that your PDF writer has a different default paper size. In your Word document, click on File, Print, select your PDF writer then click on Properties, Advanced. The paper size here needs to be the same as the document's Word paper size.