This is just my personal opinion. I believe that credit cards are just a way of getting a lot of money out of you, especially for younger people when the APR rate goes up. 17% is pretty high. If you have a credit card, pay things off immediately, or else that $100 horse blanket turns into a ridiculously expensive dress that you are still paying off 6 months from now.
I went to college for a semester and I had 2 loans. One for $1,000 and one for $7,500. With interest, my loans went form $1,000 to $1,500 and from $7,500 to a little over $8,000. I've been paying them back on time for almost a year now, and while it's taking forever to get rid of them, making payments on time, and not paying them off when I had the ability is helping my credit grow. My fiance told me, it's not how much you pay per month, it's how long you are able to be on time with your payments.
Just be careful with credit cards, because unlike a check card you (not you, but a generalized you) get from a bank where you can only spend as much money you have in there, you can spend a whole lot more with a credit card, and when you get the bill, you may not have the money to pay for it, which in turn could lean to just the opposite happening (instead of getting a credit card to up your credit, you're actually hurting your credit)
That's just my 2 cents though.
Edit:
Just did a quick search on google for pros/cons of credit cards.
http://www.ocf.berkeley.edu/~knffjw/...nsproject.html http://findarticles.com/p/articles/m...7/ai_n15762682 http://ezinearticles.com/?Pros-and-C...Cards&id=89585 
