For the introductory part, I like 3rd person perspective, to get a feel for things. Having to extrapolate basic ideas about the setting from 1st person right from the beginning is a little tedious (and I can't imagine how 2nd person works at all).
However, for flavor text later in the sourcebook, I prefer 1st person, as it allows you to see what it is like to *be* there, which may give some good ideas for roleplaying.