well i hope you have the answer by now... but if not here it comes
firstly i must say i am not a gnutella developer, but i read most of it's specification and protocols.
1)no, gnutella doesn't have a central server like napster , that's the nice thing about it, it works in a totaly distributed env.
2)well, basically you are supposed to find a host cachea friend, some IP address someone gave you on a chat etc.
the trick is to find the first IP address after that your in, and you can find your own connections.


hope this helps,