You can either go to 'About This Mac' in the Apple menu (top left) and then click 'More info'. This will bring up the system profiler.
You can also find the system profiler in 'Utilities' within 'Applications'.
The system profiler lists all the hardware and software, applications etc. in your mac. Under the various tabs, you will find 'hardware' where your Bluetooth module would be listed, among the harddrive and optical drives.
.. also think there is a 'bluetooth setup' utility in 'Utilities' as well, but I have no experience of this.