Here is a basic outline of how to securely copy files (SCP) via SSH to a remote computer from your local computer. This is a good and secure way to directly copy files from one computer to another without having to use email or FTP.
Open Terminal.app and set up an SSH connection by typing
If you entered in the correct username and hostname (usually a web address or IP address), it will prompt you for a password. When you type your password, there will be no visual indication that you are typing anything, but continue to enter your password and press 'Return'
When you are connected, your prompt should change and you should be able to access the remote computer.
Launch a new Terminal window or tab.
Navigate to the directory where the file exists on your local machine in the new tab or window.
To copy a file called example.txt on your Desktop to the remote machine's Desktop type:
Where the first argument is the path to the file on your local computer. And the second argument to scp is the same information you used to connect via SSH with a ':' and the directory that you want to copy into.
It will then prompt you to enter your password again, and after doing so, you will see some output regarding the status of the transfer.