One can't overstate the importance of keeping up with your account payments each month. The advantages are numerous. It affects not only your credit rating, but also the interest rate on your credit card account. It is the most fundamental aspect of owning a credit card.
If your issuing company allows online management of your account, use this as a credit card guide in itself. Make sure your records are consistent with those of the card company, particularly with regard to dates of payment.
Keep all paperwork regarding your account. This includes all significant corresponence between you and the credit card company as well as the receipts from merchants when you buy merchandise. This is an advantage when disputes occur.
Keep your social security number a matter of secrecy. Refuse to give it over the phone and - if possible - use an alternative number on your drivers license or state ID number. Credit card thieves and fraud perpetraters need your social security number to create fake accounts in your name. So make sure you keep it priviledged information.
Make sure your mailbox is secure. This is vital. A number of news sources have noted rings of credit card fraud perpetrators getting consumers' names, addresses, social security numbers, etc. from their mailboxes.
Check your credit report from one of the three major institutions on occassion. This will give you a guide to details which allow you to detect possible fraudulent activity with your credit card account.