What kind of lens do I need for night time photography? I don't want to spend mega bucks...$1000

but want a decent lens. For example, taking pictures of fireworks. Or is there a setting on my D5000 that will get me decent pictures?
In general, there is not a lot of light available during the night, so you have to make your camera "see" a lot of light. Recall that exposure of a photo consists of adjusting the aperture, shutter speed, and ISO.
Specifically for night / low-light photography, you need to use a large aperture (low f-number), slow shutter speed, or high ISO. Any / all 3 of these will increase the amount of light that your camera "sees", which is what you want for night photography.
For lenses, you'll need to look for lenses that have a large aperture (small f-number). There are many different options, but you don't have to spend thousands of $$$$$. Here are a few options:
- 50mm f/1.8, about $100 - your cheapest option and best value
- 50mm f/1.4, about $400 - a very nice lens
- Sigma 30mm f/1.4, about $400 - a very popular low-light lens on this message board
- 85mm f/1.8, about $400
- 100mm f/2, about $400
These are Canon-specific recommendations, so you'll have to look for the Nikon equivalent for these lenses. However, you'll see that all the f-numbers are small. That's what you'll need to look for.
You'll also notice that these are "prime lenses", or fixed focal length. There is no zooming on these lenses (except you can "zoom with your feet").
For fireworks, MarkBarbieri, one of the members of this message board, started a thread specifically on how to shoot fireworks:
How To Shoot: Fireworks
In general, though, to get the best fireworks pictures, you'll need slow shutter speed, like around 2-6 seconds (just a ballpark figure). Because of this, you'll also need a tripod and a cable release, too.
You might not necessarily need the above lenses for fireworks photography (I'll let others chime in on this one). Your current lens might be good enough, since you're not necessarily trying to capture something in low light. Fireworks themselves are super-bright, so your current lens should be able to do okay with fireworks.
Hope that helps.