Yes. When you normalize your data, each String will become a class. For example:
You have classes :
car, motorcycle, bike
Once normalized, you will have three different neurons that fire according to the class as such:
car : 1, 0, 0
motorcycle : 0, 1, 0
bike : 0, 0, 1
Play around with your data in the encog workbench to get a feel for it, the workbench makes it pretty easy.
Good luck!