Abigail book now! Halloween is a very special time at Walt Disney World and at certain resorts it can get booked up quickly.
Look over the descriptions of the various resorts on the Disney website and decide which best fits your needs and budget.
http://disneyworld.disney.go.com/resorts/ When you have decided and you know the dates of your trip which I beleive you do as you mentioned them above then call the central reservation number at 407-934-7639 to book a room. You might also like to consider a dining package for your family during your stay and you can see the different ones offered by clicking on this site.
http://disneyworld.disney.go.com/planning-guides/in-depth-advice/disney-dining-plan/
The biggest Halloween event at Disney in the fall is Mickey's Not So Scary Halloween Party. It is held in the Magic Kingdom on special dates. Those dates will not be publicized until about May but in the past they have had the party on at least 10/30, 10/31, and 11/1. The night of Halloween sells out quickly so keep watching for the dates and be prepared to purchase those special event tickets if you feel that is something your family will enjoy.
There are other Trick or Treat activities througout the property with the biggest being at Fort Wilderness. Guests can trick or treat among the campsites but it is the decorations that the guests bring and set up that are fantastic. Include a Haunted Carriage Ride while you are there and it will be a night to remember!
Just keep checking back for up to date information about other Halloween activities as they are often not published until much closer to the actual holiday. Enjoy the planning process and check back with us if we can help you further!