you have to owe something in order to build credit.
That's why you charge a little bit and pay it off each month.
But what about that "it's best to carry 20%-30% of your limit" that you always hear about? Well, there is an overlap between the time that your new period starts, and when the payment for the previous period is due. So, even if you pay off the balance on your statment each month, it is still possible to carry a somewhat consistent balance yet never have to pay finance charges.
As for what the minimum amount is due.....it varies card to card. Most places are 2%, but some are as high as 4%. So, if you charge $1000 and the minimum payment is 2% of the balance, your minimum payment would be $20. But, almost all of them have a flat minimum of $10 or so (say you only have a $15 balance, your minimum payment will be $10, not 2% of the balance like "normal").
As I said in your other thread about this.....if you soley want this so you can build credit, be sure you specify that you
do not want your credit limit automatically increased periodically. That's a quick way to get yourself into trouble.
Also, just as an FYI ( //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif )......if you have a credit card at a department store (JCPenneys, Kays, Sears, Best Buy, etc), that
is reported on your credit report. And having too many of those accounts open will actually hurt your credit score.