The Iowa Caucuses are Monday, February 1 at 7pm. You should arrive early because you will have to sign in and there may be a line.
Here are 2 youtube videos, one about the Democrat and one about the Republican caucus procedure. Each is less than 4 minutes long. They explain it pretty well.
Are you registered to vote? What if you are registered but want to caucus for someone in the other party? Either way just bring your photo ID and a piece of mail with your legal name and street address on it. The caucus organizers will be happy to get you registered appropriately that night.
How do I know for whom I should Caucus? Every candidate has a website which is the best way to find out where they stand on issues. Each candidate also participated in the Iowa Youth Caucus 101 program. Here is a link where you can watch a quick video from each of them:
It is your right and privilege to participate. Even if you go and don't speak to another soul there, you will be well ahead of most eligible voters. If you are comfortable enough to stand in a candidate's group (Democrats) or write a candidate's name on a piece of paper (Republicans) you will have successfully caucused. Many people have not decided who they will caucus for when they arrive at their caucus site. (See earlier post on this page for finding your caucus location.) After listening to others speak on behalf of candidates and reading the literature laid out on the tables, some people still end up not choosing anyone. That means their opinion won't be counted.
Sure you could volunteer to be a delegate or work on Party Platform Planks, since those things happen that night also, but that is above and beyond the basic caucus. (See earlier post on this page for A.B.A.T.E. of Iowa suggested planks.)
You could wait until November and just vote in the General Election. Of course, if not enough people caucus for the candidate that best represents you, then that candidate will not be on the ballot. The entire United States looks to Iowa as the first in the nation to voice our opinion. A candidate's press coverage, campaign donations, and volunteer effort all are dependent on the results of the Iowa Caucus. Many candidates have ended their campaigns after a poor showing in Iowa. Underdogs have surged and done well across the other States when Iowans chose them as winners.
Bottom line is if you don't participate then your opinion literally does not count. It is up to you.