How do I go about making a Peer2Peer program which i can use to share files between me and about 10 other friends only?

download limewire... enter in a different "connect string" (found in options under the advanced tab) and a different "connect OK string". Make it so all your friends have the same string. Then on the connections page delete the autoconnect hosts and replace them with your friends IP addresses. This will allow you to make a small network between your friends.