How many megapixels to print regular size photos?

4x6 regular size photos, no special effects. I'd like to print them in Boots this week and I always resize my pictures from many thousands to 800 wide. I've done some pre-research but it just confuses me so any thoughts?
I use Nikon D90 which has 12.3 MP

Selecting a focus point on Nikon D3100?

I already know how to change the AF modes to AF-A, AF-S, AF-C, MF. But when I put it on AF-S I don't know how to select one of the 11 points; its always on the right side. I also already tried reading the manual but couldn't find it… Please help

Which SLR Camera will be best for Global Photo Exhibitions and Youtube?

I want to purchase an entry level super zoom SLR Camera having Full HD Video Recording facility for youtube video and it can shoot photos for international Levels. My main requirement in SLR Camera is 14 to 19 Mega pixels, Full HD Recording and 90X Digital zoom (I will purchase super zoom DX Lenses additional). My Budget is around Rs 35000/- for SLR Camera body (without Lenses). I have selected two models based on my video requirement for youtube. They are Nikon D5100 and Sony Alpha A37K.

Both SLR cameras have similar features. But I prefer Nikon D5100 for making HD Video for Youtube. Can you suggest me any other model which can be better option than Nikon D5100 for my requirements.

Good Video Editor For Youtube?

Me and my friend make videos on youtube about beauty, and I really need a good video editor. But not just any video editor, i need something WITHOUT a watermark in the middle of the video, something i can crop, voice over, add effects, add background music, and keep the HD on the video. I use a nikon d3100 camera, something with good resolution, but one of the previous editors did not keep the HD and no one wants to watch a blurry bad quality video. So something that KEEPS the HD resolution.

Thanks btw if you want to check out the channel its called youngbeauty1111

Is this bad? (Shutter count)?

I recently bought a used Nikon D3100 and it has a shutter count of 16, 151.Is that a bad number for a shutter count? Will the shutter not work anytime soon?

What would be a good starter lens?

My girlfriend bought a Nikon D70 camera before Christmas, but it didn't come with a lens. Just the body. I really don't know anything about cameras, and I tried looking online for different types of lenses, but I didn't understand the differences. Anyway, my question is what would be a good starter lens for her camera? She wants to take pictures of people, so I don't want to buy her a fish eye lens. I'm also not making enough money right now to buy her a great lens. I do realize "you get what you pay for" but like I said, it's just something to start with. She wants to get into photography. I also realize that I could just ask her about a lens, but I want to surprise her.

How to eliminate dark shadows on face? (in photography, photo included)?

Hi! I'm a beginner photographer. I use a nikon d3100… Not the best, but not the worst camera. I shoot on manual, which I guess is kinda bad since i'm not using my camera to its full potential.

anyway, I mostly do self-shoots for 'outfit of the day' … One thing I've noticed is, my face is ALWAYS dark and grainy. I don't shoot using raw, but I shoot using 'Fine'. I only seem to have this problem when taking photos using my timer… Other photos I've taken of objects, nature etc seem to be high quality. Any help can be helpful! Thank you.

Here is an example --
sorry if it's a bit small, i've had to resize it

How to erase pixels in pictures on iMac?

I took pictures for a newsletter at school and I'm making the pictures professional. My camera is a Nikon D3000 and when I uploaded my pictures on my iMac, some pictures looked pixelated. How can you erase pixels in pictures on iMac?

Is this lens compatible with my camera? - 1

Is the Sigma 70-300mm f/4-5.6 DG nikon mount lens compatible with the nikon D3100?

Nikon d5200 with 18-55mm or nikon d3200 with 18-105mm?

In my budget i can buy any one of these two cameras but i'm confused which one to buy nikon d5200 with 18-55mm or nikon d3200 with 18-105mm. It will be my first slr camra. I don't have any experience in photography please help