On long rides, I take a bite of powerbar, banana, beef jerkey or pbj every 15 minutes, and a big gulp or two between bites. I usually prefer G2 or Nuun. I also stop at every rest stop and eat and drink, but I don't linger.

Definitely eat and drink well leading up to the ride, and pay attention to your body. If you stop sweating, you have a problem and should stop riding.

Recovery is also important. I like potato chips and chocolate milk right after long rides.

Everyone and every century is different, so don't worry about how long it takes someone else. Ride your ride, be sure to eat and drink enough, and enjoy it.