Maybe you don't have a DHCP server running on your network? Otherwise, OMV should get a dhcp address by default. It just might not be displayed if your dhcp is slow. ifconfig will show the address.
Installing on an N54L is the same as any other system. Install using ISO (burn to cd, write to usb stick, etc) and follow installer. Reboot and set settings you need in the omv web interface. What question(s) do you have?