I studied for the MPJE for two weeks and passed with a so-so score of 80. The exam was hard but you just have to apply as much law knowledge as you can towards the situation. Pretty much choose the answer that is best in the legal stand point even if its not something you would be comfortable with as a pharmacist, as long as its legal and applicable its more than likely the right answer (i don't believe the test tries to bait/trick you on questions). Its all within the scope of pharmacy law. I used Guide to Pharmacy law by Reiss and Hall. Its a affordable book that you can breeze through in a day. Very easy to read and has good example questions. They do a good job in explaining and giving example of narcotics, misbranded, and adulterated. The misbranded and adulterated are freeb questions on the exam so you better know the differences and how to spot them. It can get confusing but just practice with the Guide to Pharmacy Law examples and you'll be fine.
Know your narcotics. I used the DEA manual and took notes off it and just kept reading it as a base knowledge. I also went through all the control laws of nevada and wrote down the differences. If you go to the nevada pharmacy board site they have some information on controls that are important. Make a chart of your notes to read through it easier (max refills for controls etc)
I read through all the boards and regulations like 3-4 times. First time I highlighted anything that was relevant to outpatient pharmacy and control regulations (keep condensing it). If you were only a few points off chances are you were only 4-5 questions away from passing probably and will more than likely pass the second time. I would study for only 3 weeks max but study very efficiently.