A decent article for those looking to learn more about IDPA. It's often been said that the hardest thing you'll ever do is going to your first match and the easiest thing you'll ever do is going to your second match.
I highly advocate that everyone that carries a gun for defense shoot at least one match. As that other saying goes, "You don't know what you don't know" and a couple matches will definitely clue you in to what you need to work on and is a great way to test out your carry rig etc.
Getting Started in IDPA