When i take a picture with the flash, it has a yellow tint to it. Why?
Most likely your white balance setting needs to be adjusted. You didn't specify the model of your camera, so I can't tell you exactly how to change it (your manual should say).
Your camera should have several settings:
"A" or "Auto"
"Tungsten" or "Indoors" or "Incandescent"
and possibly also:
"Cloudy" or "Shade"
When taking flash pictures, the "Flash" setting should be best. If you don't have a flash setting, then "Daylight" or "Sun" will be the best.
Human eyes adjust quickly and easily to different colors of light, but cameras see light as it is, so indoor light will look yellow, outside bluish, fluorescent greenish, etc. So digital cameras shift the colors in the image to try to make white objects appear white like they would to your eye. But sometimes they mess up and don't get it quite right. That is where the manual white balance settings come in. If you play with these settings, then you will find you can improve the color quality of many of your pictures.