Help with remote Desktop

Hi guys, I am trying to connect to one of my friend’s computer using remote desktop. He has 3 computers connected to a router. He give me the ip addresses of the 3 computers as 192.168.1.100, 192.168.1.101 and 192.168.1.102. He also went to whatismyip.com and gave me the ip that showed up there. So, I want to connect to the system with the ip 192.168.1.101. How do I go about doing that? I know he has to foward the port for remote desktop in the router and set up the computers to all users to remotely connect to it. When I start remote desktop from my computer what info do I need? Any other advise is also useful to start the process.
Answer #1
as far as i know for remote desktop yo need the mac or the pc name. Try googling it.
and also make sure the computers and router is on the same network