First: You will not be serving unrelated content, only stuff you downloaded.
$ hell-serve 6666
6666 is server port, which should be open to Internet. This will launch Hellnet server.
$ hell-nodes handshake bitcheese.net 6666
If response is "Handshake successful", all is good. Server have added you to its nodelist and will announce your address to everybody, who in turn will be able to download your chunks and metatrees.
Otherwise, read the message and fix the error.