Nice idea for a site. There is definitely a very large and growing market for what you are selling.
Since you`re looking for a critique, here are few things that come to mind when I visit.
1) The logo is horrible. Specifically the bright yellow-greenish color. Almost any other color would look better...
2) Navigation is confusing. Menus and Links are all over the place.
3) Overall, it just gives a vibe of an amateurish site. Having tried myself to integrate certain elements, such as javascript menus and newsletter sign-ups into websites, I understand the frustration in getting things to look and act right. But your interface IS your product. Getting a VERY clear picture of what it should look like and how it should work is essential. Less is more.
Best of Luck,
Charlie