BitTorrent, how do I set it up and use it?

I have the BitTorrent addon, bur I cannot find any information on how to use it. Even the ReadyNAS manual doesn't give me any answer.

I open the download manager, but I don't know what to do next. Where do I find the torrents?

And what does Add Torrent From URL and Add Torrent From File mean?

There is a Support link on the page, but it doesn't lead to anywhere: Page not found.

Any help appreciated. I need to know the basic things here.

Regards

Jan