Study Strategy
The only resource I used to study for my exam was Study.com and I passed on my first attempt! You have to pay a monthly fee, but I was able to go through all the lessons and take all the practice quizzes and exams in that time so you shouldn't have to pay for more than 1 month. There is a quiz at the end of each lesson, as well as at the end of each chapter and there are half length practice exams as well. If you are planning on studying over a longer period of time, it may be better to use a different resource as this one will become expensive over several months.
Testing Strategy
The test was about the level of difficulty I expected it to be. There were some questions that I had no idea what the answer was and then several others that I felt were pretty easy. The test is passable, but requires a lot of studying! I studied a lot for this exam and it paid off. Do not rely solely on your experience in the healthcare field! Majority of the test is not common knowledge for people in the healthcare field and requires going over topics that we do not use on a regular basis.