How To Deal With The Police: Part 2 - What to Do When Arrested
Likely the best information available online is the lecture by Regent Law Faculty Professor, James Duane and the from Flexyourrights.org.
If you are an American, you are protected by the Fifth Amendment, which the Founding Fathers wrote into the US Constitution to protect the individual from tyranny from agents of the state. These two videos outline the dangers of self-incrimination when faced with encounters initiated by the police.
Fifth Amendment: No person shall be held to answer for a capital, or otherwise infamous crime, unless he or she is on presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger; nor shall any person be subject for the same offense to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.