how do I find out local IP addresses

Try WakeOnLan. It gives local network IP and MAC addresses

<http://www.macupdate.com/info.php/id/15779/wakeonlan>

If a device on your local network has an IP address, WakeOnLan will show it.

To find the IP address on the Internet side of your Router, you can use <http://whatismyip.com> or just Google "my ip address" and the first hit will be a display of the IP address for your router.

There are a few ways to to this...

You can got to the network settings for each device to get the IP address. For example, my iMac IP address:

Or you can access your router preferences to get all of the devices. For example my router:

If you don't know how to access your router preferences, you can Google the make and model to find out how to access the preferences setting.