Improving First Byte Time

[Cookie]

We ran a WebPageTest for our Magento store, and got an F for First Byte Time. I went through the documentation to get a better understanding of First Byte Time and noticed that the definition is listed as this: "The First Byte time is the time from when the user started navigating to the page until the first bit of the server response arrived. The bulk of this time is usually referred to the "back-end time" and is the amount of time the server spent building the page for the user."

What I'm trying to acquire is some practice ideas on what we can do to improve First Byte Time. I noticed there are a lot of calls to external script files, and am not sure what to attack first. The site is http://www.cookiesandcrumbs.com. Please let me know if you any suggestions.

Thanks.