So far I have been following the directions here http://www.debian.org/releases/stable/i386/ch04s03.html.en
I downloaded boot.img.gz to my windows machine, and copied it to my empty usb key.
At this line of instruction:
"mount the USB memory stick (mount /dev/sdX /mnt), which will now have a FAT filesystem on it, and copy a Debian netinst or businesscard ISO image to it. Unmount the stick (umount /mnt) and you are done. "
I don't have an existing debian system running. I do have a ubuntu system, which I'm hoping this will replace. I plugged in the usb key, and typed
"sudo dmesg | grep scsi -A 3" which another webpage told me as a way of finding where the usb key is. At the end of its output it said "[22530852.908000] sd 2:0:0:0: Attached scsi removable disk sdb [22530852.908000] sd 2:0:0:0: Attached scsi generic sg1 type 0" I think this means my usb key is 'sdb'
So now I type "sudo mount /dev/sdb /mnt", and I get 'mount: you must specify the filesystem type'
I experiment a bit and try 'sudo mount -t vfat /dev/sdb /mnt', but this reponds 'mount: wrong fs type, bad option, bad superblock on /dev/sdb, missing codepage or other error In some cases useful info is found in syslog - try dmesg | tail or so'
Now I am stuck and don't know what else to try :(