Pros
It's a very simple place to work. Clock in, do your job, clock out. I've found all of my coworkers to be very nice people that are more than willing to help if I need it. Even my managers are fun to be around. I haven't used it because I absolutely refuse to eat fast food, but employees get a 50% discount; manager meals are free. The customers, for the most part, are cordial and friendly.
Cons
Occasionally, you'll get some asinine customer that will treat you like dirt. As a female, it's worse since I'm required to wear a nametag- male customers will call you by name and give you a weird, creepy smile. The cash register system is terrible. Clocking in and logging in to a register isn't the bad part- it's that after you log into a register, you can't always control who gets on, especially if you're in a different part of the store. Some of my coworkers used my drawer several times, and it came up short later in the week. Some coworkers aren't exactly a joy to be around. Be very careful about what you do and say, as you will probably be working with one or two unstable characters. A coworker of mine attempted to ask me on a date; when I ignored him, he blew up and treated me poorly. One thing I would really like to point out is that the training is absolutely atrocious; it is the biggest joke ever. Doing fast food itself is not a hard job, but it's certainly not easy when you have no work experience whatsoever. Such was the case with me, and my first few days weren't pretty. Expect to be trailing around behind a manager or constantly relying on coworkers for your first few days.