Catch is the easiest way to use ShowRSS on the Mac. It’ll take care of everything. New shows will be downloaded as they are released.
Runs in the menubar, and won’t slow your Mac down one bit. Notification Center notifications are optional.
You can make Catch sleep at night (or at work, or whenever), organize your torrents in folders, use your favorite BitTorrent client, and update itself.
Speaks 11 languages, and you can add your own very easily.