standard tuning
i've seen him perform this song over and over so heres the chords

alternate chord (Ac)                    |-0
i don't know the name of the chord      |-1
                                        |-3
                                        |-3
                                        |-0
                                        |-0

use Am and C throught the intro

Am          C               Am
Thinking of all the cool creatures
C           Am     C    Am     C
That I will meet, tonight
Am          C              Am
Ghosts and Goblins and Witches
C           Am          C     Am    C
Roaming the streets, in moonlight
Am         C           Am
Bowls of candy and goodies
C             Am          C   Am    C
Delicious and waiting in store
Am          C           Am
Sounds of cute little footsteps
C             Am      C     G
As they approach my front door

C             G         Am           F#
Letting the childeren inside to drink beers
C             G         Am        F#
Razor blades hidden in 3 muskateers
C             G            Am      F#           C         G
Sounds from the basement of kids begging to be set free
C             G       Am        F#          
That's what Halloween means to me

Am              C              Am
Tightening the clamps that are holding
C             Am     C     Am    C
Their little heads, so tight
Am         C              Am
Putting my lips to their ears
C           Am        C     Am      C
As I whisper, please, don't fight
Am          C           Am
I promise to let you go home
C                   Am    C     Am   C
If you swear not to tell, a soul
Am       C              Am
I'll just un-tie these, I'm kidding
C          Am          C            G
Where is my chainsaw, let's rock n roll

C              G          Am           F#
A pinch of your brother a teaspoon of you
C               G           Am           F#
With the head of your sister would make a good stew
C                G              Am           F#      C      G
I'd give you a taste but your tongue's in the stew, irony?
C           G         Am       F#
That's what Halloween means to me

(stephen noises)

Ac       Am          C        G
Trick or treat, smell my feet
Ac        Am      C        G
Give me something good to eat
Ac        Am       C        G
Trick or treat, smell my feet
Ac        Am      (no music)          
Give me someone, good to eat

anyway there you have it
now on the C chord i believe that is it but it might also be:

|-0
|-1
|-2
|-3
|-0
|-0