Now You Know Crime Scenes

With hit cop TV dramas like the various CSI and Law and Order shows, Bones and Criminal Minds. everybody seems to think they're a forensics expert. But what do we really know? Now, with Now You Know Crime Scenes, we can all get the dope on:
How long does it really take to analyze a DNA sample?
Who started the first forensics laboratory?
Who invented criminal profiling?
How do you do a walk-through?