Upon my internet stumblings, I have found this site, for all things Hitchcock. Click HERE for the link. At first I was a little disappointed. It's very basic, almost like someone's class project. After surfing on it for a few moments, this director's conclusion is that the site is a great place to begin your research if you know nothing about the great director. For you script writers out there, you will be especially interested in the "Theories" section.
For screenwriters - In addition: here is a link to a blog post on "Mystery Man of Film". Good information on the element of surprise in story. Check out the right hand side for links to the best posts!! Click HERE for the article mentioned.