Setting up a VPN

I’ve set up a 3 box lab for training purposes (student learning the ropes) and would like to set up a virtual private network as my first project. I have an 8 port hub and was wondering if it was possible to set up my main box (An AThlon 1.2ghz 512meg Ram) As a VPN server to my 2 other boxes (Duron 800 256megRAM & Classic Athlon 650Mhz 128megRAm)I have scoured the MSknowledgebase to no avail 🙁
Any how to’s or step by step guides would be truely appreciated.

Regards LUKE