I promise this is 100% correct-ish, watch vid for a short intro too, I will go 
step by step in this video 
http://www.youtube.com/watch?v=WTb2s_ZPMMI

Capo 3

Note: Remember to leave the ring finger and the pinky on the first 2 strings (high 
E and B) of fret 2 relative to capo for the entire song

sorry for such a basic intro, but i got to lazy to try to figure it out all the way

Intro:
|------------------------------------------------------------|
|------------------------------------------------------------|
|---0------0------0------0-----0-----0------0------0---------|
|-----0-------0-----0------0-----0-----0------0------0-------|
|-3------3------2------2------0-----0-----2------2-----------|
|------------------------------------------------------------|

Verse: C, Em, D/F#, G

C, Em, D/F#

C, Em, D/F#, G

C, Em, D/F#

You get the idea for the verse?

Pre-Chorus: Em, D/F#, G, C, 
            Em, G, D (Palm Mute down up down up)

Chorus: G, D/F#, Em, C (Hammer your index for fun like in vid, it sounds good :) x3
Ending chorus chords: Em, D/F#, C

Immediately after "my dear brielle...": C, Em, D/F#, G...

and of course... goes into verse again with the same chords :)
Enjoy!