When you renew for the first time the hours needed are pro-rated based on when you were officially licensed.
RN's renew in even years. Look at your license. If your date is July 2008-12/31/08, you will need 6 hours. Renewal period begins Sept 1 08 through Dec 31. All new grads must have the specific hours listed on the ABN website.
Also, any CEU's that you earn AFTER Oct 1, 2008 will count on your NEXT renewal period.
Keep in mind, you want to renew as soon as you can after Sept 1. If you do not have your new license in hand on Jan 1 09, you will not be able to work. It usually takes 2-3 wks to get your license in the mail after the board has received your paperwork and money.