How to hook up two computers to two printers and print off both off each computer? -

Look for a USB Share Switch, 2 Pc s to 3 Devices. I think I got mine from Amazon.com. Works like a charge.

you need to set up networking with printer sharing, both computers will need the printers software, this may be tricky if the printers are identical.

Switchbox. Either a USB hub or a Centronics, depending upon your connections.