Newbie Help

Hello, I am just beginning to dive deeply into BGP, and I was hoping to use a simulator to start examining the different aspects of it. I think BIRD will be the easiest for me to start with, but I was hoping to find some help with how to set up my system to simulate a few routers. I'm just looking to simulate 2 or 3 AS's sharing some route information, but I'm not sure what setup is required in my system in order to do this. Any help starting out, primarily with what I need to do to my system and the configuration files, would be greatly appreciated. Thanks, Paul Kroon