The Note came out today but started shipping a couple of days ago to people who preordered it, which gave the devs a chance to root the device before the actual launch. Da_G over at XDA forums is the hero to be noted in this feat and if you got your Note today and find that rooting it has made your life a little bit easier, be sure to donate to him!
As for the actual process of rooting, it’s seems as simple as loading a tar file on Odin and flashing it to your device, but we’ll get a How-To up soon to walk you through the whole process in case you are new to this. Before actually doing it though, do know that this will increase your flash counter by 1, which Samsung could use to deny warranty if you ever needed it. We’ll get you something that doesn’t do this as soon as something like that becomes available.