How to Connect Multiple Apple Computers
- 1). Click the "Apple" button at the top of the Macintosh's computer screen, and choose "System Preferences" from the menu.
- 2). Select "Sharing" in the System Preferences window, and select the checkbox next to "File Sharing" or "Screen Sharing." Select the "+" button underneath the "Shared Folders" list, and select the folders you want to share.
- 3). Click the "+" button in the Users section, and enter the user name of the Macintosh computer you want to add to your computer's authorized user list. Alternatively, select "Everyone" in the users section, and select "Read & Write" in the dropdown menu next to "Everyone."
- 4). Connect the secondary and tertiary computers to your network, and click the "Finder" icon on your primary computer's Dock. Click the secondary and tertiary computers' icons in the Finder's sidebar to access the computers, and double-click the computer icon to open the folder. Connected computers on your network are always displayed in your Finder's sidebar.
Source...