Many Freepers here submitted their fingerprints for their pistol permits, and it took no longer than 5. Okay, you're excused. You are already in the database.
Serious question - Did they want all ten fingers or just the thumbs? Probably varies between states, I guess.
All 10, or as many as you got. Plus two plam prints. It took about 7 minutes total as I had to give two sets of prints, one for the state and one for the FBI.