Photography tips for my nikon d3000?

Tomorrow i'm going to be taking ictures at a cheerleading competition on my d3000, for those of you who have never been to one it will have similar lighting to a concert. The staium will be dark with the exception of the stage wich will be very brightly lit. My subjects will be fast moving also. Any ideas for what settings i should use?

Added (1). Last time i shot in Manual iso1600
i'd appreciate any suggestions on shutter speeds and apertures
and just about anything else

How do download my pictures from the camera to the computer?

I have a Nikon D40 camera. I downloaded my cd that came with my purchase but I don't understand how to load my pictures on the computer. I used the cable can someone tell me in
very simple language how to bring my pictures up.

Canon 70-200 f/4L or Sigma 70-200 f/2.8II?

Hi, I've been saving up for a DSLR for a while now. I'm torn between the Canon 7D and the Nikon D7000. I'm kind of edging toward the 7D, but now I'm trying to figure out my daily lens. I'm on a VERY tight budget, and I have less than 2, 000 to spend on body and lens, however, I'd like a nice lens. Which brings me to this question:
Should I get a Canon 70-200 f/4L or the Sigma 70-200 f/2.8II?
The Sigma's price has been dropped and it is now around the price where I can get the 70-200 f/4L for.
I DO realize that the 70-200 f/2.8 would dominate but take into consideration that I'm on a tight budget. If I go Canon route, I would need to get the 70-200 f/4L, no IS.
The Sigma is really attractive at this point, with it's low price. I've been trying to read up on it, but I'm getting mixed feelings. I'm beginning to wonder if I should even use a 70-200 as a daily driver. I've never owned one, and I do want to try it out in person, but I can't seem to find a decent camera store near me. I'm still considering the Nikon at this point, but I'm kind of biased toward Canon. I've used both before, and both feel pretty nice in hand.

So this is what I'm asking:
Canon 7D or Nikon D7000?
Canon 70-200 f/4L or Sigma 70-200 f/2.8II?
Am I stupid for wanting to carry a 70-200mm as a daily driver, and should I just consider a more wide telephoto?
If a 70-200 isn't the right first lens to buy, which is? (Please consider my budget)
Your suggestions, please. Thanks to all of you.

Added (1). EDIT:
I'm just a casual shooter, and I will probably take pictures of a wide range of stuff, such as sports, portraits, landscape, etc.

Problem with my Nikon D5000?

I bought a Nikon D5000 + Sigma 70-300mm DG Macro (no OS no APO)

but now, the I can't autofocus. When I half-press the shutter, the focus ring would go all the way out, and never return. But, if I put the lens cap on, it works well, the focus ring would go out and back again.

I think the problem started when I resetted the settings.

Added (1). @Pat,
I already tried that. I always make sure to explore before asking questions.

@FhotoAce,
I bought the camera plus lens used, so I can't really return it. I just hope that if there's any defect, it would be on the lens and not on the camera body.

I bought the camera last January 17. And here are my shots last January 22-23.
http://www.facebook.com/...3396667125

Added (2). @Rauf,
The Sigma has a motor. I already used the lens for two weeks. Click the link above to see the pictures. And, besides the lens was already used since November 2009. Sigma and Tamron added motors for lenses that will be mounted on a Nikon.

Problem With Nikon D90?

I have a Nikon D90 Camera. When I play the videos I've recorder on my computer, they are slow and glitchy. But when I play them on my camera, they are fine and normal.

What's wrong?

Added (1). *Recorded

Nikon D90 DSLR, how low a temperature can it withstand?

I live in Chicago and a friend and I will be going on a shooting spree (a photo shooting spree). The temperature here will be between the 19 and 23 degrees. Is that too low to have my camera exposed to the cold? We will be outside most of the time and I will most likely have my camera in the bag sometimes, but most of the time will be out. What do you all think?

We will be shooting around downtown and the lakefront.

Added (1). Ah ok, thanks for the suggestions. I do have 2 batteries.so, I'll be taking them. I just gotta make sure they're charged.

Now, what do you think of these pictures.

University of Chicago

Chicago from Roosevelt Rd bridge overlooking Metra trains

Starved Rock French Canyon in Illinois fall 2010.

I'm an amateur photographer. I would appreciate your constructive criticism.

What is a great beginner camera?

I'm going to buy a new SLR camerca this month but i need a good one that worth it.
I'm into spontaneous, good for portraits cameras as well as travel and outdoor meaning light and not to big.
So what i had in mind is Nikon D3000 or D3100 or D5000
i want it to take great photos as well as videos too. Like a balance between both.
What was your favorite beginner camera? Suggest any for me that i would like?

Nikon D3000 how would it work with it?

I was looking into buying the Nikon 70-300mm f/4-5.6G AF Nikkor SLR Camera Lens for my nikon D3000. I was looking at some reviews on the lens and said the auto focus would not work on my d3000. How would this effect my picture taking would it be difficult to take pictures with, what would the quality be like? How much different is it then the AF-S VR Zoom-NIKKOR
70-300mm f/4.5-5.6G IF-ED? Would it be worth buying?

Which is the better Nikon camera?

The D3100 or the D5000

I want the camera for mainly taking pictures of my sons in sports. Sometimes I need to take pictures in the gym or a large room where lighting is low. And sometimes outside during football at nighttime. I'm just starting to get "serious" about photography. I have taken some pics for the family. Maternity, new baby photos, wedding.etc. But have always used a point and shoot. I'm not familiar with the whole ISO settings and I have heard there's a problem with the 3100 in that area. Which camera is better and can you tell me what that ISO means.

How long will a nikon d3000 last until it breaks?

So i've had my nikon d3000 since march. And i was just wondering if it will eventually just break on its own? Or will i have this camera for like 5 years +. I never dropped it or anything. I feel like its getting worn out. I don't really use it as much as i should. Are these cameras built to last a while?