Configure your network is simpler as ISA Server 2006. You need to identify of how your network designed. Let say, you will remember edge firewall, 3-Leg Perimter and so on in ISA Server 2004 and 2006 environment.
When you first installing TMG 2010 in your 64 bit processor and operating system, you will be asked to configure your network. In my example, since I only have 1 network card attached and configured as web proxy.
Just click next on the network setup wizard.
I choose Single network adapter. Click Next
configure your IP address and so on. Click Next
and completing the network setup by clicking finish button.