This article will show you how to set up
# pacman -S deluge
Well, that was easy.
For web ui you will also need python-mako:
# pacman -S python-mako
For gtk ui you will also additionally need pygtk and librsvg:
# pacman -S pygtk librsvg
The default user for deluged, the Deluge daemon, is "deluge". You can change this in Template:Filename. Of course, the user needs to exist. In the case of the default "deluge" user, no manual user creation is necessary as the package script has done that for you.