Never own a credit card. They are all scams and are far more likely to ruin your credit than help it.
This is quite possibly the worst financial advice I have ever seen. Forget about credit. You realize credit cards provide you with free money for 30 days, that is INSURED against all fraud/false claims, and most importantly, offers cash-back (or travel/movie/your interests) rewards by using it?
If you are responsible and pay off your credit card and never accrue/pay any sort of interest, you will actually gain money by using them (through rewards, and the ability to invest the money you spent for free for 30 days!), and be protected by VISA/MasterCard/whatever against bad purchases (someone trying to rip you off).
The only people who say "never use credit cards" are those with no self control, and thus wrongly assume others have no self control either. I have never held credit card debt (unless it was special 0% offers), and every year I get a few hundred dollars just for using it (no annual fee). In addition, several times I have made online purchases, but never received the item, called VISA, and they immediately refunded my card and dealt with the seller.