Hi Elizabeth!
Shipping items from home to your resort is a great way to save on those baggage fees at the airport!
I would recommend shipping your package in enough time so that it arrives a day or two before you are scheduled to check in. I also suggest shipping via UPS or Fedex over regular mail as in my experience the USPS tracking and on-time delivery can be spotty.
You will need to put some information on the shipping label so that the resort holds the package for you. Here is an example:
Amber V.
c/o Beach Club Villas
Hold for guest arrival on: 4/10/09
1800 Epcot Resorts Boulevard
Lake Buena Vista, FL 32830
You can also include your reservation confirmation number on the label if you wish.
If you are planning to mostly ship snacks and bottled water, you may be interested in a grocery delivery service like
www.gardengrocer.com . They will deliver your grocery order to your resort. There is a minimum order of $40 and a delivery fee of $12. Shipping heavy items like bottled water could cost quite a bit - it may be more economical for you to consider a service like Garden Grocer. Visit their website and click on "Help" at the top of the page and follow the links to "FAQ - Grocery Delivery to Resorts & Hotels" to learn more.
I hope this helps!