How to take photos of movement at night with digital slr?

I have a nikon D5000 and am going to a dance ritual at 6PM when it is dark out.
how can i get good pics? People will be running, walking standing, etc.

eventually the same questiong for filming.
i have a canon HD 200 and will film a little too.

i'm rather new to some of this. Have worked in photo a bit and lots in painting, so composition is familar to me, i really need some technological advice!

You'll need to use a flashgun. Set the flash to slow sync mode. Use slow shutter speed 1/10, the flash will freeze the object (given that you are close enough) yet yo will capture the atmosphere and some background. Use widest aperture possible!

Use flash if you can but you should also look up "panning". Moving the camera with the subject while the shutter is open (when done well) will give some nice photos with implied movement. Perfect for shooting something like a dance ritual.