VPN complete step and guide

Can any one brief how and what the nessasry step in order to configure the VPN.

Currenyly, i have one DSL 500T, one desktop with windows XP located at home and one laptop with windows vista. Im often using vista as im a quite mobile user.

So i wish to configure my home is serve as VPN server and vista is act as VPN client.

Please tell me details from beginning.