I agree with Reb, I know that is the "estimate" that some programs tell you to use... but here is my take on it.
I am the SLOWEST reader in the entire world when it comes to textbooks. If i try to read fast, i end up having to reread it anyway. I usually spend 4-5 hours a night, usually closer to 4, 5 nights a week, and then If I have a test, my friend Amy comes over, and we study for 6-8 hours the night before the test. It might require a bit more time on your part, but just to begin with. Once you have a good solid foundation, you will be able to cut back on the study time. Yes Friends, it is possible to go to nursing school and have a life! (not a huge life, but atleast a decent one!)
Make sure you go out and do something fun atleast once a week, so that you dont burn out before you even get started.
Dont worry, everything seems like a huge deal now, but it will get better, you will figure it out, and things will relax again.