Do you want to send the HTML to the printer or do you want to print the web
page as it is rendered? These are two completely different things.
I suspect you want to do the latter, which doing yourself is going to be
exceedingly difficult, if not impossible, since that's what web browsers do
and web browsers aren't simple things.
What I would do is use the WebBrowser control, load the HTML into it, and
then have it print it.
Do a google search on: C# "WebBrowser Control" and you'll see plenty of
articles on how to use it.
Pete