In order to help minimize the number of port scans/brute forcing on your SSH service, its a good idea to change the SSH port to something other than 22. Use a port high up, e.g. 8000-9000 is a good range to use.
1. SSH into your server
2. Open your SSH configuration file using "nano /etc/ssh/sshd_config"
3. Change "#Port 22" to "Port XXXX" replacing your chosen port in there obviously. Save the file
NOTE: Before this next step, ensure your Disable any Firewall you are using, or update it to include your new port.
4. Now run "service sshd restart"
Done!