Artist needed to create children books illustration artwork

I am looking for someone to design/illustrate a series of childrens book for me. First and foremost, the artwork must be original and will become my property. This could be a very long term project based on how well your illustrations are. I will pay you $30 per book and I will increase that amount once I start to sell the books and make money. For your hard work, I will also give you 10% of all the sales as well for the first year of each book. You are going to sign a non-diclosure agreement if you decide to do this project. All the text material is already copyright propected but I just don't want the choosen provider to be passing out the book information to anyone before it's release. Please respond with a portfolio or demo of previous work. Thanks and I look forward to a long lasting relationship.