There are various locations in GNU/Linux in which fonts can be kept. These locations are defined in /etc/fonts/fonts.conf . Check your fonts.conf file and most probably you will find these type of entries there:
The last entry means .fonts direcotry in the user's home directory.
If you want to make the new fonts available for only one user, then copy those new fonts to the .fonts directory of that user. If .fonts directory is not there, create one first.
If you want to make the new fonts available for all users, then the best place to copy those fonts is to ...say..../usr/share/fonts
Now open a console and run this:
sudo fc-cache -f -vThat's it. There are other ways to install new fonts. But this one is quite good to live with :)