Walmart credit cards problems?

I recently got approved for the walmart credit card. I only shop at walmart and sam's club. I was wondering has anyone had problems with there walmart credit card? Also I have heard that some credit card companys send there payment bill late to the customer so therefore the customer makes a payment late and has to pay interest. Can you explain to me how you pay for your credit card bill? I know the bill comes in and you send them money for it, but can you pay at a local walmart, online with a bank debit card? etc. Also my husband says that the only way it will help your credit score is if you pay the whole amount before the bill comes in is that true? How many days to they allow you to get your payment in? 2 weeks 1 week? I would apprecite any info and additional info. Thanks so much!! Also, I said i got approved for the card it is my husbands name b/c he is the only income comming in, can i still use the card or does he have to be there to sign the paper?