How do I close empty credit card accounts?

I have recently checked my credit report and I realized I had several credit card accounts which were unused for several years running with a zero balance for some time.
I would like to close them to resolve my accounts and improve my overall credit.
I have to admit that some of the credit companies [...]

Where can I get a credit card if I have bad credit?

Can I still get a credit card secured or unsecured if i have bad credit? How can I improve my credit?

Is it better to have a secured credit card and never use it at all or to use about 20% of the credit limit?

I would really like to try to reestablish my credit over the next year or two. Even if that means only applying for a secured card and cutting it up. However, I don’t know if it is better to actually use 20% of my secured credit limit and pay it in full monthly [...]

What is the best way to improve my credit score with a student credit card? ?

I have a $600 limit student Bank of America credit card. Some people tell me the best way is to pay the card balance in full at the end of the month and others tell me it is best to leave a small balance (like around $5)because the interest rates is what eventually improves the [...]