Pros
Starbucks is one of the best part time jobs you can get. The company really values its employees, and the benefits for working just 20 hours a week are amazing. The pay isn't great, but it's better than what you'd get working at a supermarket or other similar jobs, and the tips can range from $1-2 more an hour. You also get to take a free pound of coffee home every week, and get free drinks when you're working. If you like coffee, it's a great deal. Plus, you meet some really interesting people, and in my experience, the customers respect you more than customers at other retail jobs.
Cons
You have to stand on your feet for hours at a time, which can be difficult for some. Also, there's always going to be rude customers when working in retail, so you have to be able to deal with them.