How could I learn the speaking patterns of the following groups of persons?

Writing a story. Characters have unique speaking patterns, as follows:

1 should speak like a pimp
1 should speak like a gangster (not necessary the same as pimp)
1 should speak like she is from California
1 should speak like she is from New York

Where can I find out about typical speaking patterns for those groups of people?

Clarification: gangster as in the ones from the hood. Not talking about Mafia here.