1) I know print on demand will absolutely murder your margins but offering it is worthwhile just for business development. You will find it much, much easier to get attention from the media that way. Your product is good enough to get into major newspapers if you pitch it right.
2) You really, seriously need to improve your web design. It looks like a ransom note. It should look bright, clean, safe, and inviting. You'll be selling to an overwhelmingly female audience. Many of them will have never bought anything online before.
3) Put one page of a sample book on the front page. Even a thumbnail will do. I'd suggest one with a smiling young boy. Put a handwritten note next to the thumbnail, circling him, and saying "This book was made special for Dylan. Why don't you make a book special for your child?"
4) Drop the email confirmation. Drop the password confirmation. These serve no purpose but to drastically decrease the number of users who sign up to your web site. Deck that page out with reasons why they should give you their info (what does this get you?) and reasons they should trust you (this phrasing works absurdly well: "We will not spam you.") I would consider dropping the name field -- are you going to address them by it prior to them purchasing? No? Nix.
5) The table at http://www.cookupbooks.com/my_books is confusing and meaningless to me -- and I live for selling teaching aids. Your users are going to be totally lost.
6) Find some satisfied customers and get a brief testimonial out of them. You want something that essentially sounds like "My son never liked reading, but he lit up when he was the star of the story!" -- Kyle's Mom. Feature that prominently next to decision points.
7) You are selling books at $1 / book / student. Parents are willing to pay much more than that. I have doubts about it being profit-maximizing for teachers, either. (For a point of reference, my typical customer pays $30 for a product they use roughly twice a year... and I undercharge terribly.)