I think the best thing to ask yourself is why you want to root. Rooting your phone does not necessarily imply that you're going to replace the ROM. Once rooted you can do things that you don't have access to now. For example you can use Titanium backup to backup up apps and their data. However, with Carbon Backup, it's no longer necessary to be rooted to backup apps and their data.
The most common thing people do once rooted is change the boot loader which then allows them to replace the ROM.
Because the Note has a lot of special features built into Touchwiz there are two paths to travel if you decide to replace the ROM. Path 1 sheds TouchWiz altogether and leads toward a more generic Android installation. If you take that path you may lose a lot of TouchWiz functionality revolving around S-Pen, Multi-screen, gestures, etc. Explore this path with eyes wide open before you go down it.
Path two is to install a ROM that is based upon TouchWiz so that you don't lose the Samsung features but gain more flexibility and control.
The beauty of rooting and ROMming is that if you don't like a particular ROM you just install another one.
If you're really serious about installing a ROM then you need to get out of the noob mode. You need to really immerse yourself into the process. You need to find the right forums to help you when you make a mistake and you feel panic welling over your mind. Because, believe me, you will make a mistake. I've been rooting and ROMming my phones and tablet for the better part of 3 years now and have had my share of blunders. But there's a great safety net of support out there and there's no better place than the
XDA Forums because this is where the ROM developers hang out.
While it only takes minutes to root, I suggest you spend hours studying the process including watching YouTube videos. You're doing surgery on your phone and you don't want to kill the patient out of ignorance.
Good luck and let us know how it turns out. Once you travel this road you'll wonder why you waited.