I have set up an SSH server on Parabola and Trisquel GNU/Linux before. I'll try to recall how I did it below, so I don't forget.
Trisquel GNU/Linux is based on Ubuntu 14.04 LTS. The method for setting up an SSH server should be the same as on Ubuntu.
Parabola GNU/Linux is based on Arch GNU/Linux, so setting up an SSH server should be the same as on Arch.