I have a Nikon D40.. when I try to take photographs in a darker setting, the flash works, but there's a long pause before the picture is taken, and then it turns out blurry and dark. I think I just have it on the standard settings, and I can't find an answer in my guidebook. Do you know what I need to do?

The long pause is the duration of the shutter - there was one click (you probably didn't hear) when the flash went off and the shutter opens. The second click is when the shutter closes. This happens because you are shooting in an automatic mode where the camera sets the shutter speed. The shutter speed is set before the flash is fired and because you have low light, the camera sets a long shutter speed. This is necessary if you want the background to be visible, as the flash only works for things that are close to the camera. Change to TV mode (the one where you set the shutter speed - Nikon may call that mode something other than TV (which stands for Time Value), perhaps they use S for Shutter Speed) or go into manual mode and set both the shutter and f-stop. When you do this, the entire shot will be illuminated with the flash and you will have a dark background.

If you want the background lit as well as the foreground, you need to increase the ISO, and use the smallest f-stop (smallest number, largest opening) you can, and the slowest shutter you can use without getting motion blur. The flash will help freeze the foreground (e.g. people in the foreground) and the slow shutter and small f-stop number will allow the background light to also "burn in" so your background isn't just black. This works well with sunsets.