Pros
Starbucks really cares about their employees. They're the only company I know of that gives PTO, paid sick time, health, dental, and vision insurance, stock options, AND 401(k) to PART TIME EMPLOYEES. Nobody does that! If you are a young person looking for a job that will grow you up as a person and a professional, this place is it. Starbucks will make you into a great employee and will give you skills you can carry with you and use for the rest of your career, wherever you go-- and if you want to stay there forever, you can! There are great growth opportunities, along with leadership development classes and various certificates you can earn to increase your skills and marketability as you go on. I've known so many employees who have been with Starbucks for decades and they have no intention of leaving, which is wonderful, but there's no pressure to do that if you don't want to.
Cons
Your personal experience will depend largely upon your manager. I've had 4 managers in my time at Starbucks, and they each set the tone for the whole store. I've had micromanagers and managers who could stand to be a little more hands-on. My advice-- if you end up hating your manager for whatever reason, you can always transfer stores rather than quitting. God knows there's no shortage of Starbucks stores ! Sometimes, Starbucks seems to hire people who are a little unstable or emotionally immature, and then their issues bleed into the rest of the team; and its almost impossible to get fired, too, so once someone awful is part of the team, you're kinda stuck with them until they decide to leave, which can really sour your experience. Communication could be better among the entire organization, at least at the non-corporate level.