Connecting your µBITx can be done in a number of ways. Some people will want to guarantee that their computer is fully isolated from their rig and will make or buy interfaces (Signalink, EasyDigi, etc.). Others are quite happy to wire up a cable for USB control and another for the audio in/out. In reality, transformers and other forms of isolation don’t necessarily always work. RF can get into cables or the computer directly or indirectly.
Gordon KX4Z provides some useful links for reading up on rig/computer connections:
Cheaper alternatives to signalink