The practice of signing a contract to work at a certain hospital after graduation in exchange for them paying for your education has become popular in some places lately because of the nursing shortage -- but not everyone thinks it is a good idea. Think of the practice as being similar to going to one of the military academics: you get your education paid for, but then you owe them a couple of years. You might enjoy the couple of years you have to spend working for them, but then again, you might not.
The hospital I work for (and my position focuses on recruitment and retention issues) has not gone that route for the following reasons:
1. The students might not like nursing or succeed in school -- and not graduate for one reason or another.
2. The students might turn out to be not very good nurses or desirable employees -- and then we would be stuck with them. (Please don't be offended by that: most people are terrific, but let's face it, not everybody is wonderful.)
3. The students may decide they want to work in a specialty for which you don't have an available job ... or a job with the right hours ... or whatever.
4. The students might have changes in their personal lives that will interfer with them working for you in the future (e.g. husbands being transferred out of town, etc.).
etc. etc. etc.
In other words, it's a risky proposition. Who knows what you are going to want 2,3,4 years from now? and I would be very cautious about signing your life away. Also, signing a contract with a hospital gives them a lot of power over you. They won't have to pay you a great salary, or give you a decent schedule, or decent benefits, or treat you nice, or give you the particular unit that you would like, or give you a great orientation, etc. because they already a committment from you.
Those deals have worked well for some people ... but be careful ... because they are risky.