Tips from me that don't know much about many things:
1) DO NOT USE WINDOWS XP OR ALLOW IT TO ACCESS THE NETWORK
2) Trying something like VPN that I don't have a clue about it or how to set it up.

Here a site that might be helpful. Recommanded by Sympatico NetLife. However it foucus on LAN (including wireless LAN). http://www.practicallynetworked.com