Credit is a fabulous tool, but it is also a dangerous weapon. You can use credit to improve your life, or let it take over your life. In 2004, PBS's Frontline ran a program called The Secret History of the Credit Card. While it is old, and I disagree with the secret part of it, it is a good watch and I highly recommend watching it. Keep in mind that there have been many changes to credit card rules since this program was aired.
I disagree with the overall theme that credit cards take advantage of customers and are somehow bad. As I said, credit is a tool just like any other tool. It is the responsibility of the user to understand the terms of their credit card, and to play by the rules of the card.
In a perfect world, I would rather that none of you carry a balance on your credit card. Carrying a balance means that you don't pay the entire amount due each month, and that is when interest charges are applied. Carrying a balance is also when you get into a situation where all sorts of bad things can happen: high fees, default interest rates, getting stuck if you can't make a payment, etc.
Watching this video can help you understand all the potential pitfalls of credit cards, and encourage responsible credit use. It is long, almost an hour, but it includes some awesome "cameo" appearances from people like Ben Stein, Elizabeth Warren, and Elliot Spitzer. It is a very good use of your time.
Watch it! The Secret History of Credit Cards