suggestions for birthing photography

I was asked to photograph the birth of my best friends second child. I have never done anything this important for someone so close to me. i want everything to be perfect.

looking for suggestions on filters or what lens would be the best for this. I use a Nikon D5000. I need to make sure lighting is perfect since i dont want to be using a flash (probably get annoying) it will be done in a hosital so you know the type of lighting that will be there. i have mostly just done landscape type things.

Video the event and you can get all the pics you want and you'll have sound. Lighting should be fine, as far as I can remember.

But my biggest question is WHY would anyone want a record of that mess? Be sure to check with the hospital ahead of time to be sure they allow recording devices (cameras) in the delivery room. Malpractice attorneys would tell the hospital to not allow cameras.

High iso, available light with your most luminous lens and maybe lots of post processing.