As Lars pointed out, the documentation primer is a good source to start reading. The Linux Documentation Project Author Guide is also good.
I'm not clear, from your post, on what your package is supposed to do. If users are supposed to enter HTML and it spits out Docbook, of if users will enter Docbook and you want to generate html, or what.
If you're using Docbook XML you'll need xsltproc. Last I checked (and this was a couple months ago, so things might have changed) jade didn't support Docbook XML, only Docbook SGML.