This has been asked a few times, and I just finished going through the process myself, so I thought I’d share how to set up a bluetooth keyboard with a Raspberry Pi..
First, this assumes you have a bluetooth USB dongle.
Once you’ve booted your RPi up, go into the terminal and type the following commands:
sudo apt-get update sudo apt-get install bluez python-gobject bluetooth bluez-utils blueman
Once this finishes, you can go to Preferences > Bluetooth Manager from the menu and choose your device.
Once you pair your keyboard, I suggest you make it trusted so that it will always connect on boot.