fault root password in Debian is 'root'. After you've logged in, you should change the root password and configure /etc/apt/sources.list to point to a Debian mirror near you.
How to restore Grub from a live Ubuntu cd.
This will restore grub if you already had grub installed but lost it to a windows install or some other occurence that erased/changed your MBR so that grub no longer appears at start up or it returns an error.