[Actually there may be 5 power bricks: the USB hub may need power too.]
The Acer Aspire One (tclaspire3) and Dell E4200 (Crowley) each have internal, built-in wifi, but we do not use these and they are turned off (with a physical sliding-switch on the case) to reduce confusion.
Aziraphale also has an ethernet socket and can be connected by ethernet cable to the network if convenient and if within-hut wifi is congested.
The mains power plugs are illustrated with 2 pins for clarity, but they are all 3-pin UK-style pugs in reality.
Wiring the ethernet
The ethernet cable to the Asus Aspire One blue netbook (tclaspire3) goes into the yellow ethernet socket on its own.
The cable to the expo laptop Crowley (and to Aziraphale and the printer if you want) go into any of the block of 4 ethernet sockets in a row together.