Is it book who does the intro each episode?
you mean the song?
No, back when the show first aired, they did a spoken intro each episode, explaining what was going on. For the first few episodes, it was Book who did the intro, then Mal took over. Unfortunatly, they didn't include these introductions on the DVD set, which is a shame. They were quite good.
Rats. I am a DVD boxset convert, never picked up the broadcast.
If you stream the show from Netflix, it still has the intros.