I've decided to try another Operating System on my Raspberry Pi, this is a version of XBMC specially designed for the Raspberry Pi.
XBMC is a open source media center operating system which gives quick and easy access to films, music and photos on a user interface designed for a TV rather than a computer monitor. It is also designed so it can be controlled by a remote control rather than a mouse and keyboard.
So Raspbian is installed on the SD card and the SD card is in the card slot, what's next?
Before booting the Raspberry Pi for the first time, make sure you've got a keyboard and mouse plugged in and connected the monitor to the HDMI port.
Once you are ready, connect the power via the micro USB socket and it will boot up.
As well as the choice of case there are a number of options for operating system for the Raspberry Pi.
Without getting too technical, the Pi has an ARM based processor so will only run an ARM compatible operating system. Both Windows (up to windows 7) and Mac OS X run on x86 based processors so are not compatible with the Pi. The main operating system that the Pi will run would be Linux.