Best PDF to HTML Conversion Application for OS X?

I recently had my first book published and I'm looking to upload my book onto the Barnes and Noble Pub It! System for their Nook eBook Reader. I have the book currently in PDF format (from when it was uploaded to the Kindle format a few months ago), but the B&N Pub It! System needs not a PDF to upload but a HTML file to upload.

Any ideas on a great PDF to HTML file conversion App for Mac OS X? I'm new to all of this so the easier an app to use the better.

The Pub It! instructions states it'll take files in ePub, Microsoft Word (.doc and .docx), HTML, RTF, or TXT formats but it looks like the HTML format will allow me to keep the photos from the book intact. Thanks!