Trying to Port forward Minecraft server?

http://portforward.com/

You do port forward to the local LAN IP of the PC hosting the MC server…

I don't understand the question. If your PC is running the minecraft server, then the IPv4 LAN IP of your PC "is" the IP address that you need to forward the minecraft port to (port 25565 or whatever you set for server-port= in server.properties.

Note that it is usually best to leave server-ip= blank in server.properties, so the minecraft server can bind its port to any IP on the server. That is better than trying to set the wrong IP. For example you can't have minecraft bind to your public IP because that IP address is not directly on the server (if the server had a public static IP on it you would not even need to configure port forwarding).