When someone requests one of your CDs, your CD Tower will show the "pending request, 1 hr maximum" notation, and then you will receive an email notification from SwapaCD, with a link inside to take you to your account page.
When you log in, any active requests to your CD Tower will appear on the My Account (the "Requested from Me" tab will show as default on the Main view if there are items in this category) and you will need to click "I can mail now", "I can mail later" or "I cannot mail" on the request in order to accept or decline the request.