
Bjørn Røyrvik |
In general, have the PCs run into the applicable NPCs at some time and place where they have no reason to be on guard against each other and can get to talking. Alcohol also helps loosen tongues.
Do not let the NPCs spill all sorts of secrets just because the PCs are talking to them: just because you like the backgrounds doesn't mean that the NPCs are interested in sharing them with complete strangers.

Warped Savant |

For the first book, with the Scorched Hand, I had the PCs meet some of the groups at a party before the lottery (at least, I think I had it before the lottery, it's been a few years).
The group dynamics between the Scorched Hand caught their attention as most of the other groups were relatively straight forward. (I think the book has brief descriptions for some of the other groups? I also had some of the groups they met not 'win' in the lottery).
Getting to know information involved various skill checks and role-playing, and some of the NPCs were more talkative and forthcoming than others. But with what they learned, one of the PCs offered Idorii a large enough sum of money during the fight against the Scorched Hand that she switched sides mid-fight.