Radley Balko has posted links and an embedded video: 10 Rules For Dealing With Police. Good advice, generally common sense -- which can be elusive under stress.
Unsurprisingly, Rule One could be paraphrased as "Don't panic." Be calm and talk nice; it costs you nothing, it's one of the very few parts of the situation under your control and will make a big difference in how things turn out. Even if you are innocent as a lamb, all Officer Friendly's got to work from is your demeanor in the moment. And you can be sure he or she will.
It's a good video. I don't care for the theme music but hey, it's free.
STANCOR 10P TRANSMITTER: UPDATE 12
12 hours ago