I found the most wonderful Disney tutorial book on how to draw their princesses! It contains detailed information on how to draw Cinderella, Snow White, Aurora, Ariel, Jasmine, Belle, and Tinkerbell!
My most favourite Disney princesses are Ariel and Jasmine. This was my very first attempt - not counting the attempts to do both these princesses when I was nine - to draw them Disney style.
I'm very happy with my Ariel, but I think Jasmine's eyes should have been wider and her lips fuller and smiling.
The book is called "How to draw Disney Princesses", and it's available on Scribd.