This is a short set up how-to for the system I use, from blank SD-card to functioning Tvheadend server.

The system is based on DietPi, at first I tried Raspbian Jessie Lite, however it was not light enough for my taste, DietPi is really well finished and much better suited for a headless system than the Lite version of Raspbian. This list convinced me to switch to DietPi.

1. Download DietPi
2. Install the operating system using the instructions detailed here
3. Setup DietPi by following the instructions here
   1. Take a look at the dietpi.txt file on the /boot partition, you can set up a lot of things prior to the first boot, such as Wi-Fi credentials, which is especially useful for a headless Raspberry Pi 3
   2. Optionally install software packages described here, none are needed for the next steps
4. Call "apt-get install apt-transport-https" to allow downloading packages over https, it will prompt some warning messages to which one must answer with a click on the "y" key
5. Install Tvheadend
   1. apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 379CE192D401AB61
   2. echo "deb https://dl.bintray.com/tvheadend/deb jessie release" | sudo tee -a /etc/apt/sources.list
      
   3. apt-get update
      
   4. apt-get install tvheadend -y
      
   5. Follow the instructions on screen and enter the username and password for Tvheadend when prompted
6. Configure Tvheadend
   1. Go to the URL of the Raspberry Pi, port 9981, something like http://192.168.1.160:9981
   2. Under Configuration, DVB Inputs, Networks select Add
   3. Select DVB-T Network
   4. Enter a dummy name, for example "Television"
   5. Under Pre-defined Muxes select "--Generic--: auto-Default"
   6. Click Create
   7. Go to the TV adapters tab and select the Realtek RTL2832 (DVB-T) adapter
   8. Check the Enabled checkbox
   9. Under Networks select the previously created network
   10. Click Save
   11. Select the Muxes tab
   12. Wait for the system to scan all the frequencies, it will take a while
7. Save the channels
   1. Go to Configuration, DVB Inputs, Services
   2. Select Map All
   3. Click Map
   4. Go to the Electronic Program Guide, it will populate the programs of the mapped channels

From there you can discover all the functionalities of Tvheadend, it is truly a remarkable, feature complete, piece of software.