Take your time.
Give up? You aren't alone. Lots of people I have spoken to have no idea how a caucus works.
John Edwards himself explained the process to me (after I had read about it and nothing sunk in) and I still have questions. My husband spent two evenings on the interwebs reading about the caucus process to fully get a grasp of the concept.
Thankfully, I stumbled upon a very clear and relatively concise explanation of the process, and here it is:
On January 3, more than 100,000 Iowa democrats in precinct meeting places across Iowa to vote for the candidate of their choice. There is no absentee ballot, no secret vote—you have to show up in person and declare your support for everyone to see. (Side note: When I met Edwards last month, he said that Iowa Democrats were some of the most liberal Democrats in the country, even more liberal than in San Francisco. He got razzed a little for saying it, but if you think about it, it's true. If you are an Iowa Democrat who is going to brave a chilly evening to caucus, you probably are going to be the cream of the liberal crop, as it were—and far more progressive than their NIMBY, all-talk-no-action SF counterparts. But I digress...)
At 7:00 PM, supporters will gather in designated areas for their candidate (think of it like each candidate gets a corner of a room). The precinct captains will have 30 minutes to argue why their candidate is the best.
Candidates who do not receive at least 15% of the vote are declared nonviable. Their supporters may either go home, remain undecided, or choose to support another candidate. Caucus participants are given 30 minutes to decide whether to realign. (This is why the top candidates are soft-selling themselves to supporters of Dodd, Biden, and Kucinich).
Delegates are assigned based on the number of supporters a candidate has. Caucus chairs then call the Iowa Democratic Party to report the delegate counts. The whole process is open, meaning friends and neighbors know how everyone votes.
The Republican caucus, also on January 3, is a more straightforward secret ballot.
(source: McClatchy Newspapers)
And there you have it.
Still not clear? Watch this video.