Taking sport shots using Nikon D5100?

I've been asked to take photos using this camera at our school's basketball game. I've taken still shots using it but am really confused as to how to take action shots of the players. Can anyone give me advice on what to do?

You need a fast shutter speed, no slower than 1/500th. To achieve this you'll need to use as fast/wide an aperture as possible, if you have the kit lens then you're extremely limited as it's variable aperture. Invest in a 50mm F/1.8 lens, they're very cheap and will be very useful for this, and you'll need a high ISO such as 1600, 3200 or higher. Do your best to get a faster shutter speed than 1/500th as blur can still occur at that speed.
Set your camera to continuous AF and burst mode. When action is happening just hold down the shutter button and take a series of photos, later pick the best one, the one that has the peak moment of action.

For basketball, it's best to sit down below one of the baskets and focus your attention on mainly the middle of the court as that's where the gym lights are the brightest. You can switch out to your kit lens later on and capture some wider angle shots, you'll need to stay near the wide end with the kit lens to use mainly the F/3.5 or F/4 apertures. Don't go to the more "zoomed in" end as it will cause your aperture to drop to F/5.6 and will make your photos too dark.

Well the first thing to do is increase the ISO setting to at least 2000 ISO if its indoors. You also need to have a minimum shutter speed of 1/400's of a second to be able to "freeze" the action.

Your lens needs to be "fast" to. If you don't have a good prime lens that can open up to at least f2 or more then your going to be in for a surprise. Fast lenses are a must for sports photography. If your shooting indoors with poor lighting then you will have a very hard time getting anything at all.

Finally set your AF to AF-C and set your focus point to center weighted metering. This way the camera is able to track your subject instead of just focusing once. Also with center weighted metering your camera will use its cross type focus sensor to track moving subjects in the center of the frame.

If your still using the 18-55mm kit lens or 55-200mm kit lens and your shooting indoors then your ISO setting will have to be increased to about 4000ISO. You will get noise in your shots but at least you will be able to capture and freeze your subjects motion.

I'd also invest in a good mono pod to to prevent camera shake. The VR on the kit lenses helps but it won't always work.

If you are shooting cross court, you need a lens that is at least 200 mm.

Shooting from the base line, you need a wide angle lens, like a 24-70 mm

This is why you see many pros using two camera bodies so they can quickly switch to different lens lengths without needing to actually take the lens off a single camera to replace that lens with another.

You also need to make sure that your cameras white balance is set to match the lighting in the gym

Here are two samples. You will notice that in one cas I used a shutter speed of 1/500th second, ISO of 3200 and lens aperture of f/2.8. The other was shot at 1600 ISO at 1/250th second. The Photo Info says that my white balance was in manual. Actually I set the white balance to 3130 degrees Kelvin.

As you can see, there's some blur when shooting at 1/250th second.

I also shoot in RAW so that I can later process them in a batch using Adobe Lightroom so I can add keywords, my copyright notice, contact information and any lens corrections.

Shooting at the peak of action will also help prevent blur