Recent versions of Publisher have built-in utilities. If your version does
not, then look for one of the many freeware applications--I use pdf995, and I
have heard good things about CutePDF. They install as printer drivers and
show up in your dropdown list of printers, so they are very easy to use.
There is a dialogue box which allows you to choose where to save the PDF.
Thus, they can be used to create a PDF from any program which allows you to
print, not just Publisher.
Bruce