Once you are verified through Apple and have your ADC membership show up on your Assets page in your developer account, you can access the hardware store by through the link on this page:
http://developer.apple.com/membership/usa.html
Note the lowercase "m" in "membership." Navigating through Apple's developer site leads you to a page (with a capital "M") that won't let you into the store. More info
here...I e-mailed Apple about this on Thursday and received an acknowledgment that it was being forwarded to the proper folks, but they still haven't fixed the site.