How hard is it to upgrade from Nikon D40 to Nikon D3100?

I have had my Nikon D40 since 2006, i love it, but it is time for an upgrade.

i really like what i have read about the Nikon D3100, i would keep my D40 but i have had some people from school ask me about selling it to them.

i was going to sell my D40, (I'm 15 so an extra couple hundred dollars will go a long ways) then buy the D3100. But my sister told me that she heard it was really hard to figure out the D3100, and that i should not sell it at least until after i get the D3100 (that way if i get a job, or i need to use a camera i can go to my D40 so i can use a camera i know all of the buttons to.)

what's your opinion? (sell my D40 before or after i buy the D3100)

Color bar on RAW photographs?

I just shot some photos on the RAW file format, and on every photo there's a pink color bar on the top side of the photo. Is this normal? And how do I prevent it from happening again?
I use a Nikon D3100.

Is Nikon D90 still a good camera? - 1

I'm going to buy a DSLR in a few months and it's going to be my first one. I was thinking about D7000 but I realized that i can't afford it, so I decided to go with the D90. But it was first released in 2008, so it is a bit old. Is it still a good camera or should go with the D7000? Or do you have any other recommendations for a beginner?

Nikon cameras! What to choose?

I'm a poor student who's looking for my first (second-handed) DSLR. I'm just looking for an easy camera as I just want to take quality pictures during my trip around europe!

I thought a D3000 would be good enough, but then when you have something newer like a D31000, I thought why not use more $$ on that?
And then there's a D80 or D5000.

Any thoughts?

Nikon d3000 not focusing?

I have a Nikon d3000 and all of a sudden, it's not focusing. Everything is blurry. I've tried fiddling with the settings but nothing is changing. Any idea what's wrong with it and how I can fix it?
Any help is greatly appreciated.

Computer won't recognize my camera?

I'm trying to get pictures off my camera, but every time I hook in into my computer with the usb cord nothing happens. I even have tried taking out the memory card and putting it into the slot on my computer, but nothing's coming up. What could the problem be?
my camera is a nikon d5000

Where can I get a new lens?

I have a Nikon D40 and the little plastic bits that hold the lens on are snapped, I want to buy a new lens but I don't have a lot of money I can spend on it. Does anyone know where I can get a lens to fit my camera that's not too expensive? I'm not really fussed about the lens, I just want my camera to work at the moment.

Photography? Some helpful tips and suggestions for outdoor photography please? - 1

I'm an aspiring photographer. It is my hobby. I'm basically into taking photos for stock. I already do have 4-5 images on fotolia. So I do have an idea what kind of technical aspects are to be met. Of course the aesthetic and conceptual aspects but that's a different thing.

I'm buying Nikon D5100. Now the thing is that I want to get on a local site which is like getty in India. It requires dslr images only. So I'm buying a dslr. Moreover I also wanted to get on shutterstock and maybe Istock.

I have decided to shoot outdoor photography. Mainly nature and portraits of some of my friends. I do not have studio like equipments so I can't shoot portraits indoors. I don't even have a backdrop. Basically would shoot them in a shade and against the woods or greenery or in a park.

I ONLY HAVE A TRIPOD, ENTRY LEVEL DSLR (WITH 18-55MM LENS) AND PHOTOSHOP. THAT'S IT.

So could anyone please give me helpful tips and suggestions or perhaps some guidance on how to go about shooting portraits outdoors with the equipments I have, such that they are eligible for stock too? Trust me, I'm a diploma in photoshop so post processing and taking care of CA and Noise and some other aspects isn't difficult for me.

I want help with how to deal with natural lighting. Also how to come out fine as far as sharpness shadows, details of the subject and other similar important aspects are concerned.

You could even touch the topic of ideal location for such outdoor portrait shoots which are very important as far as background is concerned.

I have some ideas about the concepts though. Basically, what all should I keep in mind and how should I shoot my friends' solo portraits and group portraits outdoors such that they are eligible for stock TECHNICALLY? (Please keep in mind the only 3 resources I have.)

A detailed help would be very very much appreciated…

Added (1). I would just be having the 3 things I mentioned both for portraits and nature. I don't think I can get a reflector or something by then… So please answer keeping in mind the only 3 things I have.

But extremely helpful tips 1st poster.

What setting's do you use for Nikon SLR for low light setting?

I have a Nikon D5000 and sometimes when I'm in a restaurant at night where there's low light, and I take a picture it comes out really blurry and It sometimes takes a little longer to take the picture (which makes it blurry)
I have a piano concert to go to soon and I have a feeling that there's going to be low light but I want to have perfect results.
Please tell me the settings of the camera so that it won't be blurry.

Added (1). I'm going to a piano concert to take pictures for the pianist. He hired me to do them.

I have nikkor 70-300mm 4.3x zoom lens is that fine for d3000?

I have nikkor 70-300mm 4.3x zoom lens is that fine for d3000?