No, there isn't one spot to get the coupon codes. Google what you're looking for. I searched on "fat quarter shop coupon code" and that site came up with a code. There were many listed, some were out of date. I do it for wherever I am shopping at, like Overstock, etc.
when you are checking out, if it has a place to enter a coupon code (sometimes called promotional code), go to another browser window and search for one.
I just saw that below this thread on the links at the bottom it is coming up with coupon code links. :D