This article from Truthdig kinda, sorta, explains how the caucuses work. The author insists the entire process is a promotional and marketing fraud. Read the entire article and then decide. Or, forget the whole thing and just go along for the ride.

As a native Iowan, I am not going to say that the caucuses are top-notch, but I do not think they are a fraud per se. Now that I live in Minnesota, I rely on information from my parents and my numerous brothers and sisters. What I like about it is that there is a type of instant run-off voting that occurs. My mom caucused last time for Kucinich, and she will likely do so again. In 2004, after he did not have sufficient delegates, he endorsed Edwards. Thus, my mom ended up an Edwards delegate. All of the candidates who were not "viable" sent their people to Edwards, which is why he won Iowa in 2004. A chaotic scene, but you can pick your favorite second-tier candidate, and still end up voting for a viable one.