If these 3 computers already have Internet, and in the same location, they can already talk to each other. Next step, configure Windows, if that's what you are using, to allow sign-on users permission to access those folders.
If these 3 computers already have Internet, and in the same location, they can already talk to each other. Next step, configure Windows, if that's what you are using, to allow sign-on users permission to access those folders.