This new operating system comes with your choice of Archlinux, OpenELEC, Pidora, RaspBMC, Raspbian and RiscOS. Switch between O/S by holding down the "Shift" key between reboots. All user settings are lost if you switch between operating systems, make sure you back up your data.
- 8GB Micro SDHC card with SD card adapter
- OS preinstalled
Here is a great tutorial for setting up NOOBS