As a general rule almost all lines supply soap and a conditioner shampoo. However you need to bring your own toothpaste and so on, or you can pay their high prices at the on ship store.
Nicer lines provide more, but even NCL has the basics. I don't care for their shampoo, so I bring my own, however soap is soap. They also have blow dryers too.
I like to travel with the mini travel sizes, if anything is left at the end of the cruise, I just toss it... leaving more room in the bags for all of that shopping I did.