If you can't find much information from a male's perspective, try looking at as much info as you can from a female's perspective and look at it as empathetically as you can. Put yourself in her place and ask yourself what you think she would need from you at specific stages during the labour. I would also look into what happens after the birth, especially anything on Post Natal Depression and Baby Blues.
Above all else, just be there for her, don't leave her side, support her, encourage her and reassure her. Needless to say, that statement goes for before AND after the birth.
My partner was fantastic during the whole ordeal and I could never have done it without him. It's something about him that I will always remember and could never take for granted.
Do all of the above and all will be well. Just remember not to say anything stupid that may aggrevate her! For instance, I can't stand it when someone tells a pregnant woman to breathe when she is in labour. Breathing is something she has been doing since the day she was born so why would she forget at that particular point in her life?!
Good luck! I hope all goes smoothly for you both!