First, set the Canon 60D DSLR to movie mode using the mode selection dial on the upper left of the camera. 

To set the white balance in movie mode, push the "Menu" button located to the right of the display.

Select the first submenu (the movie submenu), represented by a still and video camera with a dot. Use the quick-control dial to select "Movie exposure." Select "Manual" by pressing the set button.

Use the quick-control dial to scroll to the third move submenu. Scroll to the "White balance" menu. This brings up the white balance setting choices. Using the quick-control dial, scroll to the desired white balance preset.

The Preset Choices are:

• Auto
  
• Daylight
• Shade
• Cloudy
• Tungsten light (or indoor)
• White fluorescent light
• Flash
• Custom
• Color temp (which allows for manual color temperature adjustment)

Determine which setting based on your lighting source.  Every camera and lighting situation is different, so a little trial and error might be necessary. Scroll to your desired white balance setting and make your selection by pressing the set button.

The purpose of white balance is to make sure the whites in your photos and videos are as truly white as possible.  Again, this may take some practice and familiarization with your camera.

This frame was captured indoors, under florescent lights, while set to the "Daylight" setting.  As you can see, the image appears warm or slightly yellowish.

This frame was captured in the same setting, but while using the "Florescent" setting.  Compared to the above still, one can notice how the whites in this picture are much truer in color.

You can also skip the built-in presets and create a "custom" white balance profile. This is a great method to white balance your pictures if you are in nonconventional lighting situations.  The first four steps are the same as the four above except that instead of a preset option, you will select "Custom."  The video below will outline every step you need to know to set a custom white balance on your 60D.

After you navigate to the "White Balance" menu and select "custom," you will need to place a white card or backdrop in the frame of the camera.  Pick the purest, most consistent white subject you can find.

Once you have your white background filling the entire screen, click "Set" in the middle of your scroll wheel, scroll to "OK" and click "Set" again.

Return to the "White Balance" menu to make sure your camera is set to "Custom."  You are now ready to shoot with your custom white balance.