as someone nearing the end of getting their ec asn degree, i can assure you this is a legit program. please check with your BON before enrolling! some states have specific requirements in regard to issuing licenses to ec grads.
past that, i would advise you to join some of the yahoo groups, they contain notes and some files with questions for you to practice. i bought at least one of the recommended books for each exam. usually through half.com. the best book by far that i discovered near my 5th concept exam, was the Saunders Comprehensive Review for the nclex-rn. it breaks everything down, gives a great overall review on all the subjects. for all the other exams, i read the main book chapters that were in the reading list. i made my notes, flash cards, and double checked the content guide to make sure i covered everything. also another great thing are the practice exams that ec offers. i think they run about 60 dollars, i can't remember the exact price. but i used it for nc5, just because i am not very familiar or comfortable with psych nursing (it's just hard for me to grasp, don't know why). those practice exams are worth the money if you are having a hard time with an exam.
i did not sign with a publishing company, but i know people who have. it's a personal decision, really. but if you do sign, make sure you're following the ec content guide regardless. don't blindly go by the study guide the publisher provides.
also, when you are enrolled, the epn has tips and such on their forums.
whew! i am really talkative today! lol. if you want more info, just pm me, i'll be glad to share more. i am finishing up my general eds (3 more classes) and then i'll take my cpne and hope to be done in the summer. i started a year ago, and have made all a's and one b. have been a lpn for 9, almost 10 years.