I've worked on projects published in both EPUB and POD in the past, and it's not always a straightforward conversion, especially with elements like footnotes.
Maybe a first project might be a script to build a printable PDF of a project, since PDF is the most common format used for POD but it could also be useful on its own--it could eventually be rolled into the build script and offered as a download option on the site. Once you have a good looking PDF, POD becomes pretty trivial.
FWIW, one hack I used to use was to use RTF as an intermediate step, since it's easier to generate programmatically than PDF and there are existing tools for generating PDFs from RTF.