Should I close credit card accounts that are paid off?

Finally, after a couple of years of barely making ends meet I am starting to make some good money. My first priority is to get rid of as much debt as I can. I have two store credit cards, and two major credit cards. As I pay off these accounts should I close them or keep them open with no balance? My credit score is around 690 only because of my high balances. I would really like to improve this number.