Code:
find /path/to/A/directory -type f -iname "*.html" | xargs html2ps | lpr
You will need to alter the command if you do not use lpr for printing.
Also, if there is a specific order you want the pages printed in, there's no guarantee they will be found in the order you want. There's no easy way around that, because the computer's not psychic. The most straightforward way to enforce page order is to give all the files in the order you want to html2ps, which means you get rid of the find command and the xargs parts, but that takes away virtually all of the automation.
If you don't have html2ps, you can download it from the author's
website. All it is is a Perl script. It has a lot of options to control how things are rendered, but the basic out-of-the-box defaults may work for what you need.
Lastly, you could bypass html2ps altogether if you like, and just
cat all the files, but that would give you un-rendered output. In other words, plain text with the HTML embedded in the text.