One of the readers of the site provided some helpful information on the tram extension to the airport, which is pretty inexpensive - see the comments on the post above.
You can find a map of the route. I’m guessing for most tourists, you’ll want to take the tram via to Stazione or Unità, as these are both near key transport and tourist destinations.
You can find a map of the route here:
I know I’m late to the party; internet searches will net you some other blog posts that have more detailed information on time tables and routes.