If you use windows, then you will need to download a free program called “PuTTY” from here: http://www.putty.org/.
Having downloaded and installed PuTTY (it's a single file called putty.exe), run the program.
Enter the IP address that you found earlier and click “Open”. This will give you a warning (the first time) and then prompt you for the user (“pi”) and password (“raspberry”).
The ssh window will then be ready for use.
For a good example of how to use ssh to remotely configure a raspberry Pi, take a look at this tutorial: