Once it is downloaded you will then run the putty.exe file. You will
then be prompted with the connection box. Fill in the correct username,
password and hostname of the server in which you wish to connect to.
Once you have connected to the server you should have an open secure shell to your server.
For OS X you just need to open Terminal.app which is located in in your Utilities directory in the Applications folder.
Double click on the Terminal.app to open a new
terminal session. From there you will type in the below command to
initiate a ssh session to your server.
If this is the first time ssh'ing into your server you will be prompted
to save the RSA key fingerprint to your computer. Simply type "yes" and
press enter. Once this is done you will be asked to enter in the
password for the user on the server in which you want to connect to.
Type in the password and press enter. (Please note that no text will be
displayed when typing in your password.)