Search for truetype fonts on the net -- anything you like. After you've downloaded and unzipped them (if needed) you have at least a couple of options for installing them. Here's a random site I just got from google:http://www.webpagepublicity.com/free-fonts.html
Font files end with .ttf
If you use the KDE desktop, you can open them by simply clicking on them. This will pull up a previewer showing the font and there is an 'install' button in the lower right hand corner. You can install into your home dir or system wide; it will ask you. I normally choose personal (home dir) as they then survive O/S re-installs.
The second way is to use PCC as root. Under the system tab you will see a font installer. This one can only install system wide and not for just one user. Still, it's easy to shift select dozens at a time for install.
Also, be sure that you tell dolphin or whatever file manager to show previews for fonts as that makes things a lot easier when browsing your collection.
All your programs, including inkscape, will have access to the new fonts you install using either method.
BTW, they end up in your home dir in a dir named '.fonts' if you install for personal use only.