Nikon D3100 help? Bonfire photos?

I'm new to photography and the new proud owner of the Nikon D3100. I will be shooting in many different sporting situations (football, baseball, indoor volleyball, etc.) as well as portraits for friends and family. This fall I have been asked to take pictures at a friends birthday party and it will be a bonfire in the woods. I was wondering if there's anyway I could get quality pictures without using a flash at the bonfire? I'd like to use the most "natural" light from the fire as possible. If someone could tell me step by step directions to setting up the camera, it'd be greatly appreciated.

Added (1). I have an 18 to 55mm lens and a 55 to 200mm lens. If that makes a difference…

You need to combine a slow shutter speed with the flash. Set your camera to shutter priority and try some shots at speeds from 1/4 sec to 1/30 sec. Set your ISO at 400. You will get some ghosting at the slower speeds so just find a look that suits your taste.

You might struggle with such low light. You'll need to put your camera on a tripod to start with and probably there'll be a need to ramp up the ISO to quite a high value even with a large aperture of around f/2.8 although if you are using a kit lens your max.aperture will be more like f/3.5 or f/4 making the photography even harder. Unfortunately at high ISO the D3100 isn't that great, and your images will be quite noisy. Be prepared for motion blurred images, but if you can get someone to sit still enough you may get some acceptable images. You've found one of the limitations of an entry level camera, but don't let that hold you back!

You can use flash, but also taking in the ambient light as well… Look up slow sync and rear curtain sync in your manual. This can make for some interesting shots.

Unless it is a huge fire, you probably won't have enough light to do much in full darkness. If you can shoot before twilight you can use a faster shutter speed to avoid blur. After dark you will have to ask people to be very still unless you are going after motion or camera shake blur. Do not be afraid to raise your ISO.

Here are a couple of regular campfire shots from my Photostream:

Exif data there's ISO 2000, 1/10 @ f/3.5
That is a slow shutter speed, and your subjects will be blurred a bit even if they try to hold still.

A portrait:

A shot before dark:

And here is a shot just for fun using rear-sync flash and a flashlight:

Use a flash for some to get the people captured who are there. Then you can try playing around to see what you get. Lanterns, glowsticks and flashlights all make additional light sources to play with. You will probably have a lot of wasted frames, but you will also get some cool shots that will be keepers. Have fun and happy shooting!

I'd consider adding a 35mm or 50mm f/1.8 AF-S lens to your camera bag. The two lenses you have are very versatile, but are limited in low light situations and portraits. The 35mm f/1.8 Af-S is available for under $200, and I've seen several of them selling on Craigslist or Ebay used, for very reasonable prices. The F/1.8 aperture will let you shoot in lower light, use a lower iso (more detail, and/or use a higher shutterspeed. For portraits, you'll be capable of great bokah. Currently, though it's inexpensive, it's one of my favorite lenses.

Here's some shots using that lens with "bonfire" in my search.
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And here's some portraits.
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