To add a channel open the tab Channels and press News Template button. New template will be created and you can edit it with the opened dialog box. See its description in Channel Template dialog.
If you find a channel in Internet that isn't in Online News Screensaver database and could be interesting to the other Screensaver users, write us to 
and give us its exact URL. We'll add this channel to our Screensaver database as quick as possible.