I've heard two conflicting things: One is that you should pay your entire credit every month, and the other that you should maintain roughly %30, %50 (it varies by who you ask) of your available credit still indebted, but pay off the minimum amount every month.
Is one of those answers universally true? Does it depend on the credit card?
And two more tangentially related questions: I've heard that if you're late in paying bills that are unrelated to the credit card (for example electricity or cable) then it doesn't affect the credit history. Is that right?
And -- do you have to ask for more available credit or does it happen automatically? I currently have $500 (and have had for over a year); is there a special thing they're looking for take to me from $500 to $1000?