You would create a vSwitch on the host or a DVS (licence permitting) then add these adaptors to that virtual switch on creation and associate a VMnetwork port group to this switch.
Then with your virtual machines in the network drop down you can select the VMnetwork you created which will enable the VM traffic out of those nics.
Then can be started in Configuration, Networking, Add Networking --> Virtual Machine --> Select the NICS you want for the vSwitch.
Assuming you already have a default vSwitch (vSwitch0) and port group (VM Network), what you need to do next is:
You can also create a separate Port Group on the same vSwitch (though I don't see the need since you only have one VMNIC):
What steps do I need to take in order to get one (perhaps eventually multiple) virtual machines to use this adapter?
Do you mean to give that specific adapter all the way up into the VM guest operating system? Or do you mean that you want one or several VMs to use that interface for their network traffic in general?
Okay, that has put me on the right track. I've set up Networking Configuration as below.
Those two fiber adapters on vswitch1 are physically connected to a new and completely unconfigured NAS box, which possibly explains the red crosses. There are no lights flashing or solid on any of the fiber adapters on either end so I believe this is a NAS issue, I can probably temporarily connect the NAS box to another machine with an RJ-45 just to configure it, so for now this does not appear to be a VMware issue.