As far as Networking goes you need to read Chapter 5 "Configuring Network Connections" in Using VMware Workstation (PDF) so as to have a better understanding of the VMware Virtual Network Infrastructure and then if using Bridged you should disable automatic bridging on VMnet0 in the Virtual Network Editorand assign a specific Host network Adapter.
Also have a look at: Understanding networking types in hosted products (1006480)
As far as "What should the NAT's SubnetIP/Mask/Gateway be set to" VMnet8 is configured by default and if you want to use a different IP Address then change it in the Virtual Network Editor to match what you want to use in the DC.
