How to copy the image file to an SD card
You will need to know the device name of the SD card, for example
/dev/mmcblko, or /dev/sdb. If you are already running a Puppy Linux,
this is easy, as the drives appear on the screen when you plug them in
-- also, run "probedisk" in a terminal window to see exactly what drives are in your system.
This image file requires a 4GB SDHC card. Class 6 or higher is
recommended. Cheaper cards that may be somewhat less than 4GB, although
labeled as 4GB, should also be ok.
For the example of the card being /dev/sdb (be very careful, make sure you don't write to your hard drive!):
...make sure card is not mounted!...
# unxz --stdout raspi-sd-4gb-sap6-5.96.img.xz | dd of=/dev/sdb
...always type "sync" afterward, before removing SD card.
July 1, 2012
If you are running MS Windows, there is a tool for copying an image file to an SD card, refer to raspberrypi website.