I've had 3 root canals...no pain at all! The "toughest" (if you want to call it that) part is keeping your mouth open for such a long period of time. However, they do have devices that can help prop your mouth open. Do what I did and make it fun...hold a mirror up so you can watch too!
Seriously, don't sweat it at all...you'll be sore afterwards, but it's not an intense pain or anything. The old days of painful root canals are long gone...