The best way? To pay for a host (like
this)
If you're set on hosting it yourself, as far as third party programs your main choices are
SAPP or
GandanurAs far as forwarding ports:
portforward.comYou shouldn't need to fully install HaloCE on the server computer (unless you want to), you'll need some specific files from HaloCE in order for it to run, if you want that, I can tell you which ones.
Here's a few Halomaps articles about the subject to help you:
Running A Halo CE Dedicated ServerDedicated Server CommandsEdited by Somone77 on Jun 26, 2013 at 08:41 PM