| In order to give yourself the least amount of headaches (since Microsoft and Adobe generally don't play nice together) - I would strongly recommend saving your Word file as RTF.
Then open up PageMaker and set up your booklet. All you're going to have to do is determine the page size, and the general layout of your right and left-hand pages (PM works on the "master page" concept). Select the entire RTF document and place the text in PageMaker. You'll then have to adjust the page breaks and formatting (hopefully not too badly mangled in the transfer).
The function you then want to do (after you've fixed up the book and saved it, of course) is in
Utilities > Plug-Ins > Build Booklet
That will make an additional file with the pages laid out properly for printing. You may have to generate a PDF for Office Max anyway, because a lot of these places can't handle anything but Word and PDF files for printing. | 
