New to Photography, have some questions!

Hey guys, I got a Nikon D40 today!
I am still new to Photography in general, so I'm still learning.

I got this one problem though.
When I take a picture, in the preview screen it looks like a picture you would see if you took it with a webcam. Kinda "fuzzy". Instead of a clear crystal image, it shows an image that are like made up of dots.

Is it because of my camera settings, the way I took it or something to do with the lighting?

Thanks in advance!

I think what your talking about is noise
If you have a high iso setting it will cause more noise. Lower the iso setting therefore, but this will mean your pictures will be darker in low light settings. The iso basically decides how sensitive your camera is to light.

Its because of the tiny lcd screen, i myself have a D50, which are the same camera, just the body on the D40 is smaller, the shots on the screen are being shown at like 300x300 pixels, when they are 3000x2000 (give or take). The shots you are taking should be fine, in theory.