If you've decided to open a new credit card ... Do you want to earn rewards? A rewards credit card is a great way to earn cash back, points or miles on every purchase you make.

But just how old do you have to be to start earning points and miles and building up your credit score with a credit card?

The way they work is by charging your card ... of times that you're planning to spend more than normal to open a credit card and put your big purchases toward the minimum spending requirement.

With all that credit card debt already piled up, should consumers open another credit card now that the holidays have passed? It can make sense for some consumers — but only if they open cards ...