I stole this from the POP thread and the schedule listed is from 2011 but it should be able to give you a good idea as to what can be expected:
POP Century Halloween Activities
Candy Apples
Trinkets
Trick or Treat bag decorating
Popcorn Hands
Coloring
Temporary Tattoos
Cookie Decorating
Lollipop Ghosts
Face painting (extra cost)
DJ 4:30-8:30pm
Haunted Maze dusk-9pm
Halloween Goofy 5:30-8pm
Costume Parade 7:45pm (kids walk around the pool area)
Trick or Treating 8-9pm
Ghost Stories 9-10pm
*credit goes to stitchlovestink for the above*