In your /etc ditectory is the network folder. In the network folder is the interfaces file that contains all the data used to configure your network. The default configuration is dhcp. You can configure this file manually, to a limited degree, via the administration>>network panel. For most applications dhcp will be fine, and therefore you can leave your default configuration. If you want to setup a static ip, for your primary ethernet card, use the administration>>network configuration menu. You can set any static local ip outside the range of the dhcp configuration on your router. You can disable the dhcp of your router to set static addresses for the lower safe range. The default dhcp range is typically 192.168.0.2 to 1982.168.0.50. After disabling dhcp you can disable network manager in the preferences>>sessions configuration menu. If you are using a bridge and tap I highly recommend direct configuration of your interfaces via the /etc/network/interfaces file. Please refer to my previous post for more information about bridge and tap configuration.