My Nikon D90's manual mode is dark, what are good settings to change it to?

I just bought my Nikon D90 and I'm new to it
My manual mode is taking extremely dark pictures when there's no natural light
What are some good settings to change it to to make it not so dark?

In manual mode you must adjust the shutter speed, aperture, and ISO yourself in order to create a correct exposure. If you don't know how to do that, either take a beginner's photography class, or buy and read a book called understanding exposure.

Try experimenting in A mode. The dial will change your Aperature ( Iris size of your lens) and the camera will do the rest of the thinking. Start memorizing the settings for when you are in M mode.

If the camera is taking dark pictures then it needs more light. You can either open up the aperture so that it lets more light into the lens, press the flash button to engage the flash or take a longer shutter speed exposure to give the lens more time to gather light (note: the longer the shutter speed the more still you will have to hold the camera). You can also play around with the white balance settings and exposure settings. Remember in low light settings you may want to boost your ISO to either 400 or 800. If you are not familiar on how to do this, then read the manual.