Import public gpg key
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 74A941BA219EC810
edit /etc/apt/sources.list and add:
deb http://deb.torproject.org/torproject.org trusty main
Install tor
apt-get install tor
Start (it ususally autostarts after installation)
service tor start
Enable on boot
update-rc.d tor enable