SSH ip address connection

So I'm trying to connect to my computer remotely using terminal and OSX Leopard. I know my IP address and when I go on a different computer on a different network. I type in SSH (my ip address) then hit enter. It has a screen so I type my Admin and password but it doesn't do anything then after a few minutes it says connection timeout. Am I doing it right? Is there something else I should be doing? I even tried SSH with my friends IP address and it's doing the same thing.