Hey there everyone!
It's me again, asking questions about a World of Darkness mortals game. Yet again.

This time, though, my questions are a tad more specific. Taking the players from my D&D group who are the most dedicated to roleplay and character development, and adding people who I know enjoy writing their own stories and acting to that mix, I've formed a group with which to run a mortals game. While the setting is still up in the air, I feel that I should begin work on at least the preliminary stories as well. As this will be my first time STing a game, I feel that I should enlist some sort of help from people who may be far more experienced. What sort of preliminary stories, sessions in which the characters first become aware of the supernatural, have you used in the past? How have you kept the characters in the dark, dispensing information slowly so as to have more questions come out of every answer? What sort of over-arching plots have you used in such chronicles?

Furthering this, I would also like to ask for specific help with my group. I'm finding I'm having trouble with deciding what sort of preliminary stories to tell for each character (so far the consensus is that the preliminaries will be done individually, or in some cases in pairs). The cast consists of a Disillusioned (in the bored and apathetic sense) Stockbroker, a Disgraced Biologist, A Park Ranger, and a Photographer Who has been experiencing frequent blackouts (one of which caused the death of his family in a brutal car accident).

I can run the photographers with little issue. He'd like for it to involve seeing a shrouded figure surrounded by ravens or crows right before the blackout which killed his family. I may have that happen, with the figure being a spirit of death or somesuch.
The other three characters, though, I am not so sure about.