cyrillic fonts

In Trisquel's repository, there is a package named "texlive-lang-cyrillic". I believe it provides the fonts you want. You can install it from the "Synaptic Package Manager", for instance.

To write in Cyrillic, you may only need these two lines in the preamble of your LaTeX document:
\usepackage[utf8]{inputenc}
\usepackage[russian]{babel}

Thank for answering.
But I already can write Cyrillic in Latex. What I want is to use different fonts, for example "liberation serif" or others. Right now I can only use the default font (I do not know what font it is).