Many people have the misconception that purchasing a DSLR means better flash photos. While this is true with the right equipment, it is certainly not necessarily true when pulling the camera out of the box.
Pop Up Flash

Most entry and mid-level DSLRs come with a pop-up flash. Be sure to read your owner’s manual to see how to operate the flash. Some DSLRs require you to press a button to open the flash. Many will automatically open the flash for you if you are in auto-mode. The pop-up flash is very similar to the flash on a point and shoot camera, only it isn’t quite so close to the lens. You do not have the ability to rotate or chance the angle of the flash. The flash will always be directed straight at your subject and give you those same overexposed faces.
Read your manual. You can probably turn down the output of the flash to get more natural looking photos. You can also change the timing of your flash if you are taking a longer exposure. Other ideas for more natural flash-light would be to purchase a diffuser for the flash, or simply make one out of translucent paper.
Speed Light

If you take many indoor photos that need a flash, consider purchasing a speedlight/speedlite for your DSLR. A speed light is simply an off-camera flash purchased separately that attached to your camera’s hot shoe. This way your camera can transfer data to the flash like zoom length and when to shoot the flash. The benefits of speed lights are numerous. You have the ability to rotate the flash head in almost any direction. Try bouncing your flash off the ceiling or a wall. Remember that the color of wall you are bouncing off of will add to your photo. I usually choose white walls for that reason. I find that inside a house, bouncing off the white ceiling makes for some very natural photos.
Before you buy your speed light, take a moment to look at the options on the flash and your camera. Is it possible to use the flash wirelessly with the camera? This is a great feature because then you will have the ultimate creative control of where the light is in your photo. If not, you might be interested in a cord that extends from the flash to the camera so that you can position your flash elsewhere.
Pro Cameras
Pro DSLRs will usually not come with a pop-up flash as the pros will almost never use that function of the camera. If you do decide to buy a pro-level camera, remember to buy an external flash to go along with it.