You should look into Hamachi. It is free for up to 5 devices. It creates a VPN tunnel between computers without having to configure anything. As long as the computers have the client installed, are connected to the internet, and are added to your "network", you are able to access network resources like shared folders, printers, etc.
I did this for an accountant who had 2 offices and no server at either office. Setup Hamachi on the Windows 7 computers at each office and her laptop, added them to her "network" and she is now able to access all her network resources from either office and her laptop when she is out of town. Works great!