CONGRATULATIONS!! If we didn't care, we wouldn't be nurses or on this site. It is an important accomplishment to become certified in a specialty. Some are afraid to try because of the risk of failure/co workers finding out. Once again, congrats!!
I personally just studied on my own. THE IBT was made purposely harder than the sit down computer based exam. Remember, you have 30 days and can use all the internet and book resources you want. You can even have the doctors you know help you. LOL