The following instructions apply to the recent Ubuntu versions (14.04 and later).
This help article is for Linux/Ubuntu If you use a Windows computer then read this article.
USB connection
Make sure you have the Developer mode enabled on your Sailfish device. If not, see this article.
Check that you have the SSH password set in "Settings > Developer tools > Remote connection".
Connect a USB cable between you PC and your Sailfish device. At the moment of connection, choose "Developer mode" at the device display.
SSH session
Open the Terminal on Ubuntu. Create SSH connection with the following command:
ssh nemo@192.168.2.15
Type your SSH password now.
If a warning about "Remote host identification has changed" appears then give the command
ssh-keygen -f "/home/xxxxxxxxx/.ssh/known_hosts" -R 192.168.2.15
(where xxxxxxxxx is your Ubuntu username)
Now connect with SSH to the phone:
ssh nemo@192.168.2.15