I have added a second network interface to my interfaces file in /etc/networking but can't get the interface to come up, I get the error

"SIOCSIFFLAGS: Cannot assign requested address" when I issue the command "ifconfig eth0:0 up". Any help is much appreciated.

Here is what my interfaces file looks like:

auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
address 10.0.0.10
netmask 255.255.255.0
network 10.0.0.0
broadcast 10.0.0.255
gateway 10.0.0.1
# dns-* options are implemented by the resolvconf package, if installed
dns-nameservers 10.0.0.1
dns-search remotecpu.com

iface eth0:0 inet static
address 10.0.0.12
netmask 255.255.255.0

You indicate you added a second NIC, but are trying to create an alias for the first NIC. Are you trying to bring up a new physical interface, or add an alias to an existing one?

rather than
ifconfig eth0:1 up
Which is expecting an address to be assigned as part of this command

why don't you use
ifup eth0:1
which will use the address assigned in the interfaces file

the command you gave it is incomplete, it's looking for an address, but you never provided one to assign.