Mike,
I haven't been completely successful in this, but I have a web-enabled database where users can run reports on the data within HTML, and then click on a link which outputs the same results into a pdf file.
The original information was all posted to a MySQL database via HTML, and the query is submitted via HTML. I could have run the report straight to pdf I suppose, but it was designed so that you could have a "quickview" version of the report only generated as HTML. If you have any specific questions, I would be more than happy to share what I have, as most of the rest of the PHP stuff I have gotten from here anyways! It's always good to give back to the community.