Main riff: 

G |---------------------------------------| 
D |---------------------------------------| 
A |---------2-2-2-2-2--3-3-3--------------| 
E |-3-3-3-----------------------2-2-2-2-2-| 

Then (2nd verse on) throw in this every other: 

G |---------------------------------------| 
D |---------------------------------------| 
A |---------2-2-2-2-2--3-3-3-3/5-5/7-7----| 
E |-3-3-3---------------------------------| 

Very simple and a lovely song - only got the album a few hours ago but it should be right.