I know that this might seem like an unusual way to study, but in my opinion, i really think that this technique might help you.
Kaplan offers you a prep course to help you prepare for the USMLE Step 1. I think that you should take the course in order to prepare for the NBDE Part 1. (The USMLE Step 1 and NBDE Part 1 cover the exact same material, except for dental anatomy.)
Kaplan's USMLE step 1 course has a series of seven beautiful blue books that cover topics such as microbiology, immunology, biochemistry, gross anatomy, pathology... all of these topics are on both the USMLE and the NBDE.
Then Kaplan has these audio lectures that go along with the seven beautiful blue books. Listen to these lectures, take notes onto the seven blue books.
(Be careful each of the Kaplan USMLE step 1 blue books is 500 pages long!!! )
Then Kaplan has a question bank of maybe 2,000 questions for the USMLE step 1 and another question bank for the NBDE Part 1 that is also 2,000 questions long. Do these questions. Do both the Kaplan Q-bank for the USMLE step 1 and the NBDE part 1.
Then you will DO SO WELL on the NBDE Exam.
The reason why I suggest Kaplan USMLE Step 1 Course is because the NBDE Part 1 is just like an easier version of the USMLE Step 1. Both board exams cover the same material, but the only difference is the level of difficulty. The USMLE step 1 is much harder than the NBDE Part 1.
Why don't I recommend the Dental Decks? The Dental Decks is a bunch of flash cards with a million random facts written on the back of each of the flash cards. How awful is that? The Dental Decks just seems like a random collection of facts - and each flash card is filled with a million detailed facts. How can you possibly learn from that?
No, i am not a kaplan representative. I know that they are extremely expensive to have to buy Kaplan test prep, but it is worth it. totally worth it.
I have friends in medical school who have taken the USMLE Step 1. They have taken a look at some NBDE Part 1 practice exams, and they can answer the questions SO easily.