This section will be short and sweet. Hands down the best free online money center is Yodlee. I would link others, but I can't imagine needing anything else. With Yodlee, you put in your account number, and in one easy to use page, it will show your current balances, and if you have a payment due.

You can also have them send you an e-mail every time one of your minimum payments is due. This is extremely important so you can keep your 0% money at 0%, if you miss a payment, it will default to a higher percentage. Yodlee makes it almost impossible to miss a payment if you check your e-mail on a regular basis.