Depending on your class, you may need your textbook, your drug book, and your lab (nursing implications of various diagnostic tests) book. (My instructors typically have us do group exercises in class when you need those items.) You'll probably also have a binder with class papers / powerpoints, and a notebook for taking notes. And you'll also have a pencil box/bag with pencils, erasers, pens in different colors, half a dozen highlighters, a small stapler, and sticky notes in half a dozen colors. And you may or may not have a laptop computer with you.
And that's just for one
If you want to carry all of that on your back (plus a purse, for most women), go for it. I much prefer to roll it behind me -- everyone says that nursing's going to kill your back, but it's really nursing SCHOOL
that starts the downward spiral!
Carry-on bag, rolling briefcase, rolling backpack -- doesn't really matter which you have, but you're GOING to want something with wheels of some sort.