If you want to know Belfast it is probably enough to buy a little booklet and read it through before you arrive. Still, there is something to a guided tour that no book can ever replace, the fact that you see something live and get to hear about it at the same time. In Belfast they have a very popular sightseeing bus taking you to the must popular places and sights in Belfast. In this way you can see them close up and get to hear the interesting stories and legends behind them at the same time.
The hop on-hop off bus in Belfast currently have 18 stops and they will also take you to the Titanic Museum and other places a bit outside the main city center. In many cases this is much easier to use as a mean of public transportation than using the simple city buses.
Tickets for hop on-hop off tour in Belfast: