When you arrive at the jail there is usually a lineup area, such as a yellow line. It may be inside or outside the jail. Other arrestees may be told to also get on the yellow line while you wait to be processed. Meanwhile, the police officer may be attempting to make contact with the motor vehicles division to obtain a positive identification or obtain further information on you.
If they don't process you immediately, you are thrown into what is called the "drunk tank." It's usually a concrete room with a big metal door. Drunk tanks are generally small rooms with a toilet and some benches. They're pretty dark - usually lit by only a single light bulb.
When it is your turn to be processed, they will call your name and tell you it is time to be "booked." They want to take your picture and fingerprints. The process is simple. They want to take several sets of fingerprints. One goes to the Federal government, one goes to local law enforcement and they may also take a third set for another agency.
The officer has you put your clean fingers into a pad of black ink and says, "Just relax and let me do the work." He rolls your thumb and then your forefinger, then your remaining fingers. He does the same procedure with your other hand. Then the officer makes another set with all your fingers held down at once. He'll make several sets. Then he'll want you to sign the document. Sometimes they want you to sign the document before you give them your prints so there is less chance of your damaging the prints when you sign. They are not asking you to sign a blank form to defraud you, but only to make their job a little easier.
They won't force you to sign - I know of no one who has been compelled to sign the prints. If you don't want to sign, somebody will write, "refused," and initial it. I have done it both ways. I have signed it, "Paul Revere," and I have refused to sign.
As far as taking your picture, they have you hold a plate with large numbers on it while they snap the picture. They don't care whether you smile or not. Some jails take additional pictures to use "in house." You might be standing on the yellow line and without them even asking, they'll snap your picture. Four pictures come out of the camera at once - and these pictures follow you wherever you go. They use one picture to make a tag which goes onto the door of your jail cell.
I can't give you an absolutely correct way to handle fingerprints and pictures. We've gone many different ways. If you say "no," to fingerprints, you may be brutalized. Some people have said, "As far as I'm concerned, it's not a salvational issue, it doesn't matter whether they have my fingerprints or my picture." And they simply submit to the booking procedures like everyone else. Others refuse to submit.