How do I convert a publisher newsletter to acrobat in order to publish it to a website?

Install Acrobat. This will provide PDFMaker.
With the Publisher file open use "Adobe PDF" to use PDFMaker.
Use PDFMaker's configuration dialog to configure.
Use PDFMaker to create the output PDF.

Note that a given Acrobat PDFMaker is supports specific Office application versions.
See: http://helpx.adobe.com/acrobat/kb/compatible-web-browsers-pdfmaker-applications
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Be well...