Confused

So, I'm studying for NCLEX. For my school we had to do an ATI live review class. The woman in charge of the class taught us several things we all kind of disagreed with as we were taught differently in nursing school. But, I thought to myself, she's telling us what NCLEX wants. I might also add she very rarely have us rationales for the answers.

So now I'm reviewing with my Saunders book I got. Two of the things the ATI woman said are not lining up with what Saunders says and I was taught in school.

They are basic questions and I guess I'm worried on who to believe. I tend to believe Saunders because it is directly in line with what I was taught. Every question counts and I'm afraid that if these subjects come up, I'll miss it and it won't advance me to higher level questions. One has to do with MRSA and precautions and the other has to do with delegating urine specimens to a UAP. Also, what Saunders and I learned in school line up with my experiences on my unit. But I know NCLEX is not real world.

I hope it makes sense what I'm asking. I've only made it through the first 4 sections of my Saunders book but have already found two discrepancies.