Party is over and I have had a chance to recuperate, I thought I would share with you what we did.
First I divided the participants into three groups. Harry, Ron and Hermione. They were told that they had receive information that one of the Horcruxes or Hallows was in a certain location.(Grandmas house -the Burrows, Aunt Janeens-Grimwauld place, My house-godricks hollow) then it gave them a page number for the 7th book to read in order to figure out what they were looking for. Each team had three location and three items they had to get. I had a "death eater" posted at each location. Now here is the tricky part. All of the team members had to stay under one large "invisibility cloak" while looking for their items. If they got out from under the cloak, the death eaters would grab them and keep them. They had to get out of the car and stay under that cloak while they looked and stay under while they returned to the car. Each team had a symbol.. Harry- goblet of fire, Ron -the flying car, Hermione - the deathly hallow symbol. At each location there would be cards with the team symbol on it. Some card had clues to the location of the item they were to get. Some would say, "try again" or "keep looking". Each team got three items different from the other teams. A hallow, and two horcruxes. ie. stone, wand, Griffindor sword (They all ready had the cloak so we swapped for the sword) , ring, locket, headdress, snake, diary, and goblet. Once they had all the items they would return to the party. Once they returned to the party.... we had placed all over the party location, copies of all the chapter art for all seven books all over the barn. we handed the team a book and they had to find all the pictures for that book. Once they had found all the pictures they got there prize. Whew! I hope that made sense. If you have question I'll try and clarify. Everyone had fun I think.