Port forwarding

I am trying to set up port forwarding to allow me to view a Foscam wireless camera (F19821W) when I am away from home. I was able to get it set up wirelessly in my home, but I have been unable to figure out how to do port forwarding. I feel like I'm so close! I have accessed AirPort Utility and gone to the settings in Network. I have also added a screen sharing - VNC port setting. This is where I get stuck. I don't know what the settings are supposed to be. Are the ports supposed to be the same as the camera? I realize I can make them different, but I am going to make them the same. I edited the port number that was there to the port I used for the camera and saved it. Then, when I'm taken back to the previous window and select "update" I get a message that says, "The device and its network services will be temporarily unavailable. Are you sure you want to continue?" Well, I don't know if I want to continue because I don't know exactly if I did what I was supposed to do or if I'm going to lock myself out, or lose my internet connection and not get it back. I don't know the consequences of clicking on"update". Also, what is the Private IP Address supposed to be…I don't mean specifically. But, how do I decide what that is supposed to be?

Any help I can get is greatly appreciated. Thank you.

Cayleen