Help with my Nikon camera; focus is blurry?

I recently purchased a Nikon D3100 camera, however one thing is bugging me.
It makes so many of my pictures blurry. I currently have it set on P and the quality on RAW, image size large, but sometimes when i take a single picture, the shutter stalls and it comes out blurry (when the damn shutter opens, that is… )
When i use the lense to zoom in, it goes completely blurry and the flash is making things worse. Sometimes it works beautifully, other times, I want my money back.
I dunno… am i just a dumbass and am missing something completely obvious? or should i take it back to the store?

PS i have a sample pick of me and friend on her roof at night.we took this pic several times over and it got blurrier and blurrier each time- even with a flash.

Here's the pic:
http://s694.photobucket.com/albums/vv301/victoriatodd94/?action=view&current=DSC_0239.jpg
>>> Help with my Nikon camera; focus is blurry?

Best Nikon lens for under $500?

I have a Nikon D5100 with a standard lens which is nice, but I find it doesn't have the kind of zoom that I'm looking for. I'd like to do nature photography but that's requires a good zoom since you can't always get close to the animals. What Nikon lens would you suggest for under $500?
>>> Best Nikon lens for under $500?

Nikon d5100 mid telephoto lens?

I dont really like the 18-55 kit lens, it's too slow and i'd like to upgrade to something faster. The d5100 doesn't have a built in focus motor, so the lens must have a built in motor. Any recommndations? Oh, i'd like to keep it under $400, and used will be okay too
>>> Nikon d5100 mid telephoto lens?

Which country own nikon camera company?

Which country own nikon camera company?
>>> Which country own nikon camera company?

Red stripe on grip of cameras?

I've noticed a lot of people have dslrs with a red stripe, is it just for a certain brand or series.

P.S: Should I get the nikon d3100?
>>> Red stripe on grip of cameras?

Is this a gramatically correct statement? - 3

"I'm upgrading to the Nikon D90 camera in a few days. I'm excited"
"I'm upgrading to the Nikon D90 camera soon. I'm excited"

--
Which one is better? Do you know a better way to formulate it? Is it a better word to use instead of "excited" ?
>>> Is this a gramatically correct statement? - 3

How to shot a picture like this with nikon d5100?

What setting i need to set during this kind of shot?

http://d2f29brjr0xbt3.cloudfront.net/908_isovaperture/1.jpg
>>> How to shot a picture like this with nikon d5100?

Canon T3i + Nikkor lenses?

I just bought a Canon T3i, which I intend to use mostly for video.
I have a few nikkor lenses, that I've mounted on the camera with a fotodiox adapter (the cheaper kind).
They are all G-type lenses, so I ran into a problem with aperture from the start.My biggest problem is that when I turn to the video preset, there's an error that says "Ensure a lens is attached". If I press it again, it let's me shoot the video but only for about 9 seconds, and then it stops automatically.

I have a SanDisk 16GB, class 4 memory card.
I'm pretty new at this, so it might be something obvious?
Added (1). Again, it's not important why I have the camera, that isn't going to help anyone. I actually have a Nikon D90, and it supports video as well.So, the concern isn't in why I didn't get another Nikon.
>>> Canon T3i + Nikkor lenses?

Buying an used Nikon 5100?

My friend is selling his D5100 with the kit 18-55mm lens for $500. He's had it for about a year.Do you think this is a good deal? Thanks
>>> Buying an used Nikon 5100?

What kind of calculations can i do for a camera?

Im seeing the matter of geometric optic and the teacher ask me for some calculation of the following cameras

nikon 7000
nikon 5100
canon T3i

but what kind of calculations should i do? any ideas? thanks
>>> What kind of calculations can i do for a camera?