Hello, Angelica!
We actually purchase the exact items we need for our stay on our own and then ship them to our hotel, with our own name in the "ATTN" line. At check-in, we simply tell the Cast Member that we should have a box (or two...diapers take up a lot of space!) waiting for us. The address for
Pop Century is 1050 Century Drive, Lake Buena Vista, FL 32830. Be sure to put your name in the "ATTN" line, followed by (Guest) and you should have no problem. With the cost of checked bags these days, it's been less expensive to ship these items than to pack them in a checked bag. :-)
Friends of mine, however, like to order items from Garden Grocer (gardengrocer.com) and have been happy with that service. According to Bell Services, Garden Grocer, or any other outside delivery service, will be allowed to deliver your purchases to Bell Services, where they will be held in your name. You'll need to be present for that order to be brought to your room.
Please send more questions as you think of them! We love to help Guests plan the most magical vacations to Walt Disney World!