How make this connection?

Connect them all to a (gigabit) Ethernet switch and connect one port on the switch to a LAN port on a normal home router.

The switch handles all traffic between the machines while the router provides the DHCP configuration service & common internet connection. (It will still work for the LAN setup if the router does not have a working internet connection)

Decide a name for the "workgroup" and set that name in the workgroup option on all the machines.

Also enable network sharing and discovery.

Any folders created on any machine and set as "shared" should be visible on all other machines.

For a printer, you want one with an Ethernet port. Connect that to the switch too and install the driver on all machines.

If you get a multifunction printer/scanner/(fax) they you can also scan from any and (with fax) send faxes directly from any computer.

Use a router to create a LAN for you.

Its a devices that's stays on 24/7 connecting devices to and from your LAN... many support Wireless also.

N00B