There is a similar question here: How to get shared computers' IP addresses in OS X 10.7?, but it doesn't answer some of my questions.
THe biggest problem is it says to fill in "MyOtherMac" with the name of the other computer found in the first step. The only unique names in the list were the instance names, which have spaces and colons, which are not accepted by the common specified.
It also doesn't specify how to find computers that are not Macs on your network.
So my question is either: "How to execute the answer in the previouse question" or "How to get IP address of all users on a network on Mac OSX"