If you are arrested you have the right to remain silent. You also have the right to contact a lawyer. If you are offered these rights you should take them. I see many people who think that they can explain their way out of trouble, not knowing what evidence the police have against them.

It is much better to remain silent at the police station until you have spoken to a lawyer. Even if you refuse to answer questions the police officer may still try to encourage you to answer questions. In my experience it is very rare that someone who has been arrested can persuade the police officer that arrested him or herself that its all a big mistake and they should be un-arrested.

When arrested, the police are entitled to:

take your finger-print and palm-prints;
take a photograph of you;

You must provide the police with your full name, address and date of birth if asked.