Nikon d3000 how to shoot for soccer?

I got a nikon d3000 to take pictures of my kids soccer games but i can't seem to get a clear picture as they are running by. I know it has something to do with shutter speed and stuff but i'm all too very new at this stuff. Could someone help me figure out the settings i need to set it to? Also would like to know how to get clear pictures at night when they are playing.

Sunshine, that's easy. You'll need to check your book for where exactly to go but.
In your shutter priority, set it to 1/1000 and let the camera decide on aperture. Fire away, you'll be amazed about the "freeze".

Night, that's a different matter. Cameras live on light and night time shooting is usually all about time
exposure and most cameras don't do well with normal settings at night. I own a Canon 1000D and I do a lot of night time stuff - but, it's all time exposure.

One thing you might try is a new lens - 50mm f/1.2 or so. These lenses aren't cheap - the Canon version is $1, 200 but they do a very nice job in low light. I don't know what your budget might be but this type of lens could be very helpful at night. You may still get some blur but it won't be nearly what you'd get with a standard lens. The 50mm has no zoom so you're stuck walking to or away from your subject.

You need a lens like the Nikkor 55-300 mm lens to be able to capture the action closeup.

You also need to be sure you are shooting at at least 1/1000th second to freeze the action. Depending upon the amount of lighting you have, you will have to adjust the ISO upwards to assure that shutter speed. Opening your lenses aperture all the way will be a help, but under an overcast sky or at night under the lights, a high ISO may be necessary.

Here is a shot shooting American football at 1/800th second. This was shot with a 300 mm lens.