Does a hot shoe flash enhance the quality of pictures?

I'm new to photography so I don't know:/
I bought a Nikon D3000 a couple months back and now we're being advised to get a hot shoe flash. I realize how much they are, but do they really do anything to the quality of pictures?

What's the difference between the automatic flash in the camera and a hot shoe flash?

The hot shoe is a bracket on the camera that you can physically mount an add-on flash to. "Hot" refers to the fact that the bracket is electrically wired to trigger the add-on flash when you take a picture.

The flash that you add will put out more light and can be adjusted more, including which direction you point it. The flash will be further away from the lens, which will reduce red-eye, and you can aim the flash to bounce of the ceiling, which will reduce the washout that you can get with a flash.

You can usually bounce them off walls and ceilings, or fire them off the camera entirely (with additional hardware).

Yes, the difference compared to the built in flash is like night and day. Take a look here:
http://www.kenrockwell.com/.../sb400.htm

Biggest difference is way more control over the direction of the lightg. And yes, that does make a LOT of difference

Yes, they do. And they do it even better if you get them off the camera.

There are only a few hotshoe flashes that aren't much more powerful than the built in flash on your camera. That is one difference… Most hot shoe flashes have much more power. Another is how far the flash is from the center of the lens… The further the flash off the lens axis, the less chance of redeye. You can bounce the flash off the ceiling, or wall, or reflector, as needed. You can use off-camera flash(es) to create texture, where your built-in flash destroys texture.

External flashes can be just as automatic as your pop-up, such as the Nikon SB-600. Or they can be manually controlled, or have their own controller in the flash itself.

The quality of your images will be no different.

If you do not shoot a lot of event photography, you really don't need to spend $350 for an external flash.

Instead you may want to look at buying a second lens like the 55-200 mm or 55-300 mm. The lens will extend your shooting range to include action, sports and some wildlife.

Here is what an external, hot shoe mount flash will do.

* it will reduce the amount of redeye in photographs of people. This is because the flash tube is further off axis from the lens.
* external flash units have more output than the on-board camera flash
* if you buy a Nikon dedicated flash, you will find that it has many more features that work with your D3000 than a generic flash

It's sort of a bracket you put on your 'secondary' flash.

Then attach a new flash.

Only if you use it off camera. That way you can control directionality & add modifiers to it (umbrellas or softboxes) to soften the light.

If you use it on camera you will still have flat (frontal light) but you will be able to bounce it off walls/ceilings if (a) you're indoors and (b) they're not too far away and (c) they're a neutral (white, cream, pale grey) colour. A hotshoe flash is as said already, far more powerful than a built in flash.

You do NOT have to get a Nikon flash - for about £80 you can get a fully manually adjustable flash and a set of radio triggers to fire it off camera.