Thank you Prof Yaffle.
I added the following entry to the /etc/apt/sources.list file:
deb http://apt.tvheadend.org/stable wheezy main
I initially tried using "raring" instead of "wheezy", but I got an error during the installation process. "saucy" isn't a valid directory at http://apt.tvheadend.org/stable/dists.
After saving the sources.list file, I ran the command:
sudo apt-get update
I could see that it was able to successfully process the TVHeadEnd repository. I then ran:
sudo apt-get install tvheadend
I now have tvheadend installed. Now, I just need to get my USB tuner working.
Ivan