I would stick to the ones that are sold on the AACN site. They know what's on the test and they gear their learning materials to the test.
Years ago, when I took it, they offered a floppy disk (do NOT laugh---LOL) that had questions related to all the different areas of the exam. You could take a quiz related to a specific area of the exam (cardiac, endocrine, etc) or take a 200 question mock test. It was a great learning tool because they provided rationales with each question and also told you why the wrong answers were wrong.
Not sure if they have something similar now (it would NOT be a floppy disk, LOL) but if they do it would be really helpful.
Good luck with your exam!
Look up Laura Gasparas Vonfrolio. She runs a CCRN education program and hold lectures/seminars all over the country. She also has books and DVD's of her lectures. Everyone raves about how good she is. I bought some of her stuff and I think it was awesome. She has a book that breaks everything down (like Cliff's notes.) And if you get her DVD, she teaches everything in a way you will remember it (like with jingles and acronyms). The website is www.greatnurses.com and her name is the top link if you google it. She does lectures all the time and there is a calendar if you are looking to attend one near to your hometown.
I used several CCRN review books. I HIGHLY recommend Laura Gasparis Vonfrolio's materials. If you can see her in person, even better as she sells her CCRN/CEN materials on site at a slight discount and even gives sets away during her presentations.
I also recomment Pass CCRN! by Robin Donahoe as the review CD is worth it's weight in Gold.
I took my CCRN a few months ago and I recommend the Laura Gasparis Vonfrolio book and the video. The video is a down and dirty of everything that will be on the CCRN and I will say that almost 100% of what she talked about was on the exam. Her book is over 1200 practice questions and that is all that I did. Question after question for a few months! Seemed to help!
Good luck, it is a difficult test, but if you study you should be fine!!!
PASS CCRN - the book comes with a cd of practice questions, if you can pass the practice test you should be fine on the ccrn.
that's the best resource. i thought the other stuff mentioned was ok but not nearly as important. the internet has some great resources also- check out emcrit.org, ercast, emrap.tv, emergency medicine cases, icu rounds. they all have free podcasts/videos lots of icu stuff.