Format and setup the SD card:
dd if=Kingston-4G-NewIT-v1.0-debian-squeeze.img of=/dev/sdg bs=1024k
See if it's OK (fdisk -l /dev/sdg)
Now try to boot the plug.
ssh into it firstname.lastname@example.org
Edit /etc/hostname to change the host name.
Edit /etc/hosts to change which host name is localhost.
Check that /etc/network/interfaces is correct (eth0 gets its address via DHCP)
Change the password by running passwd
Set the date!
$ sudo apt-get update