How long with a battery for a Nikon D3000 last?

Question for my friend who will be doing a wedding from 9am-10pm

He has 2 batteries for the camera but planning to get more just in case. Is one more okay or should it be two more>?

Nikon D3100 video shooting problem?

1) I have a problem with aperture its not going below 5.3
2) Whenever I shoot a video its not recording more than 10min's

Nikon D3100 lens on Auto won't work?

I have a Nikon D3100 with a 55-300 and 18-55 lens. Whenever i have my my lens on auto, it won't shoot. And when its on Manual, it shoots fine but I'm not good at getting it focused in well. Any help/suggestions?

Camera travelbag for nikon d5000, 15 laptop and some clothes?

I was wondering if someone could suggest me a good durable bag that is relatively cheap that I can use to travel around Europe for a few days with my camera, laptop and a few days worth of clothes?

Do anyone have any suggestions? Definitely want something that I can carry on the plane and that keep my stuff safe.

Should I go with Film Phototography or Digital Photography?

Which one? In my list of choices for film is the Yashica Electro 35 or Nikon FM10.In digital the Nikon D5100. I'll be taking pictures of landscape, fun stuff… And Swimming(competitions).So which way should I go? Do you recommend any other cameras for film?

Matrix: 3D color matrix metering II for sports?

How would the nikon d5100 with the Matrix: 3D color matrix metering II do in focus tracking?

How to blur the background of a portrait photo on a Nikon D3200?

I want the person to stand out and the background to be blurred, I'm sing a AF-S NIKKOR 50mm f/1.8G lens

Will the nikon 35mm lens fit my nikon d40 nikon body?

Will the nikon 35mm lens fit my nikon d40 nikon body?

How to remove a grid on the viewfinder of a Nikon D3100?

I can't figure out how to remove it!

What camera should I upgrade to?

I have been using my old D40 for years now and it served me extremly well. However now I decided I want to upgrade to a new camera. I'm looking for a camera that can also record videos. I was looking toward the D7000 or the D5000 but to be honest, i'm not exactly up to date with all the Nikon cameras so I'm looking for some suggestions. I will be buying a used camera up to about 700$.