Step 1: Installing Deluge (torrent client)

http://www.howtogeek.com/142044/how-to-turn-a-raspberry-pi-into-an-always-on-bittorrent-box/

 

Step 2: Installing Sickbeard and Couchpotato

http://www.howtogeek.com/146410/how-to-automate-your-always-on-raspberry-pi-download-box/all/