First, install the Deluge PPA to get the latest releases:

sudo add-apt-repository ppa:deluge-team/ppa
sudo apt-get update
sudo apt-get install deluge

To install the headless version run:

 sudo apt-get install deluged deluge-web deluge-console

then run deluged to start the daemon and now you can use e.g. deluge-console to us the command line client.

To install the GUI version run:

 sudo apt-get install deluge

and run deluge.