Networking

Hey everybody,
I have a few questions about networking.
First of all me and my friend would like to network each others computers. WE live in completely differnet suberbs quite a way away and we dont want to spend heaps on running phone lines to our houses. I've heard of VPN networking and would like to know how to set it up. I have installed it from the Windows Setup (Im using 98, meaning i can only act as a client, not set up a server). My friend has created a server, but does not konw how to find the server ip...he is using windows xp. could someone please tell me how to find the server ip. And also, when i have to connect what i have to use as my usename and password. Does he have to set one up for me somehow? can you explain to me how this is all done?

Also, i was thinking about networking my current computer (Windows 98) and one that i am going to get (Windows XP). Do I have to buy special software and/or buy a Network/Ethernet card? Please explain this to me in full detail about how to set it up.

I am also thinking about networking my computer with a really old Macintosh computer. As in, really old with no CD-ROM Drive or anything. Is this possible and if so how? thank you for your time.

command box......ipconfig /all......he sets up your account......for your network id have a nic(5$)in each machine...connected to a router(only 50$)...not sure on the mac tho