The Dental Decks are very good only if you use other resources. Do not just use the decks. As one of the members here said before, the dental decks give you a false sense of security. To simply pass the test, I have seen many in my class do okay with simply just the decks. To do well one of the tasks you must accomplish with the decks is to KNOW everything on the backs of each and every card. But, again, do not use the decks as your sole study materials if you wish to do well.
To do well on this exam, never say to yourself "they would never ask that, so why bother learning it?" They have asked things in the past and on recent exams that are so far out there that'll blow your mind. Basically, do not limit yourself.
How about other sources you ask.... basically have a good biochem book, physiology, microbiology + immuno, pathology, and anatomy book (not just an atlas like netters, but something else with actual text, like moores). Don't try to read these things cover to cover. You'll never finish them. Have these at all times next to you as you are studying. Use them as resources. The index is your friend!
First Aid for the USMLE was my best friend when I was studying. I could not study without it by my side. There were things in that book that you would never think they would ask on the NBDE, but they did! It was unbelievable how good that book was for me. The problem with it is that it does not have the basics (which are very important as the real test, atleast for me, had a lot of these) and of course, it is missing head and neck anatomy. First Aid for the NBDE sucked. I didn't like the format. It had a lot of mistakes (example, it has Hashimotos thyroiditis listed under HYPERthyroidism). I still have it under my bed. I think I only cracked it open 3 or four times. Oh, and don't underestimate histology. I know a lot of people don't like it, but it is a big part of the anatomical sciences section.
Now how about the old exams? They are very important. Do not use them thinking that there will be repeats (for me, there were not a lot of repeats, maybe 1 or 2 that i remembered for every 20 questions). Use them as guides for seeing what you have to study, how you're studying has been going and fill in gaps of knowledge.
Here is my list:
Dental Decks
USMLE First Aid
Anatomy: Moores and Netters + BRS anatomy.
Pathology:Robbins
Microbio: microbio made ridiculously simple
Immuno: what ever that was in the decks and usmle first aid.
Biochem: lippincotts and some random biochem book somewhere.
Physiology: BRS physio and Guyton and Hall
Dental Anatomy: Brands, Okeson, Wheelers
Again, the big text books like robbins and guyton+hall were just for reference.
Here are some things I had, but did not use:
Kaplan book
Dental Stax
NBDE First Aid
NBDE secrets
These are just my ideas and things that worked for me. If you simply want to pass the test, this is overkill. I personally went crazy with studying. I have never, in my life, had a microbio, path, immuno, or physio class. I go to USC, and you guys all know the story with that school (no classes, just stupid PBL cases that don't help anybody). I had to teach everything to myself. I never even had these classes in undergrad.
There is no magic way to study and no special prep materials that will help. If you have the heart and the drive you can do it. If you want to get a good score, you'll know how to go about it yourself. What really worked for me was constantly saying to myself that enough is NOT enough. Every extra bit helps. Doing this helped me get a good score that I am very happy with.
Oh, and come to this forum regularly. Ask questions and answer other's questions. It really helps!
Good luck!