If you've enabled the Remote Login option in System Preferences-->Sharing, then you can SSH into your Macintosh using the same address you'd use for accessing the Mac through HTTP.
If you're acessing it from a Windows computer, you can use PuTTY. If you're on another Mac OS X computer or a Linux/UNIX computer, you can use the OpenSSH client from the terminal by typing "ssh" followed by the URL of the Mac (this would be the same name used when accessing the Mac through HTTP hopefully).