It's actually possible that the news site you're referring to doesn't provide any RDF or RSS file at all! Nevertheless you might want to check http://www.webreference.com/services/news for a more or less comprehensive list of sites on the web which provide a RDF or RSS file.
If you found any interesting news sites which provide such a backend, though, don't hesitate to send them to Frerich Raabe <raabe@kde.org> so that they can be included in future releases. Thank you!