I've read a lot about profiling, but I don't know much about how to become one. You could go to a search engine to find out more. I think that unless there is a criminal profiler who isn't too busy to mess around on this site, then your best answers will be found elsewhere. You can begin by taking psychology classes and whatnot. I think that they basically provide the details for you when there is a crime, and then you sort of piece it together. But I wouldn't do it if you can't handle looking at pictures of mutilated bodies. I mean if you get to the point where you profile serial killers. Mostly, I think, you must have an analytical mind.
Profiling began with John Douglas, you can look for some books by him, they may be helpful. Another book you may want to look for is the Gift of Fear by Gavin DeBecker. He understands the criminal mind very well and is an expert at predicting dangerous human behavior. Both of these men are amazing at what they do. Although I'm not sure exactly if what Mr.DeBecker does is criminal profiling, but it does have a lot to do with criminal psychology.