There is a white button in the header to the right, the one in the middle, that says "Drop us a line". Clicking on it will take you to the contact page. On this page, you will see a bunch of options that identify the purpose of your contact. That helps us get in the right mindset when we see the message.
Give us any suggestions, ideas, criticism, reaction, whatever is in your mind that relates to the site that you would like us to know.
Go ahead. Don't be shy.