During a recent project i had the need to install some new fonts on my Xubuntu box for LibreOffice. While searching around the Ubuntu Forums, I found the answer:
If you need to install new fonts on your Ubuntu machine, just follow these simple steps:
First, in terminal, type
sudo (insert name of your file manager)
with the default managers being nautilus (Ubuntu) and thunar (Xubuntu).
You will likely see a warning about running as root. Once you are in your file manager, go to /usr/share/fonts/truetype (for truetype fonts). Copy your .ttf files directly into the truetype folder. Once you have, close the window, go back to your terminal, and type:
sudo fc-cache -f
Wait a moment for the command to process, and you should be good to go. If you have any further questions, include them in the comments here, or ask the experts over at the Ubuntu forums.