Sigma lens for Nikon d5100?

I was wondering how the Sigma 70-300mm f/4-5.6 SLD DG Macro Lens fits the d5100? And if it does, how does it cooporate with the camera?
Last, is it a good lens? Any downsides with it?

Which lens is better? Nikon

For the nikon d3100, is the 70-300mm lens better than the 35mm 1.8 for photo shoots and party events? Which one do you prefer and why? I need a lens that will give me beautiful bokeh

What makes my pixels unsharp?

I'm using a Nikon D3200 with the stock 18-105 mm lens. I have noticed that I can't focus really precisely. If I take a picture of a structured surface at an angle, I can clearly see the limits of the depth of field, but even at its centre, the pixels are not really sharp, I can see a circle of confusion of about 5 px at the full resolution. See the image (F/5.6, ISO 100, 2s, f=66 mm, cropped):

Is that something a prime lens would solve, or a property of the chip?

Nikon lenses and nikon d5100/d3100?

So I was considering buying the nikon d5100 with the kit lens (18-55mm) but I'm mostly using the camera for photo shoots/portraits and events like parties Etc. I was contemplating on just buying the nikon d3100 body and investing in a better lens, the 35mm 1.8.Is this a good idea?

Can I get a low profile DSLR shoulder bag recommendation?

I'm looking for a bag to hold my Nikon D3200 with lens, and two to three additional lenses, a flash, my iPad, and someplace to store a small tripod. I like the Naneu bags but they don't have a place to store a tripod. The biggest thing is that I don't want a bag that screams, "Camera Bag!", like a lowepro or caselogic bag would. Does anyone out there have a recommendation? And can we keep it under $150?

I currently have a nikon d80 and I'm looking to get a new camera?

I do photography on the side and need a little better camera? What should I look at? I don't want to spend over 2000

What Camera would you Suggest? - 2

What DSLR camera would you recommend for around a $600 budget? L've been looking at Nikon's D3200 for awhile now, but I'm just not sure yet. I'm 18, so obviously no professional, but I will be using it for just about anything, I would also like a camera that has better videoing than others, (which is why I've been looking at the D3200) What other DSLR camera's have good videoing?

Why does it take longer to my DSLR to read out a long exposure image from the CCD?

I have a Nikon D3200. I noticed that shots I made with exposure times in seconds also take longer to write to the SD card *after the exposure is finished*. Images of dark scenes taken with a maximum exposure of 30 seconds take almost one more 30 extra seconds to save before the camera is ready to take another picture. I don't understand it - shouldn't the CCD be in about the same state after the mirror jumps back regardless of how long it had been opened before? Is the camera post-processing anything?

Selling Nikon, buying Canon?

This year I decided I wanted to trade my Nikon for a Canon. Perferrably a Eos Rebel t2i, or t3i. But I don't know where, and how much to sell my Nikon for? It's the D3100, with box, no damages, never dropped, with $55 case, and 16gb memory card along with 18-55mm lens.
Thanks

Added (1). I want to switch because I don't like Nikons.

Added (2). I don't need sassy replies! I'm just asking basic questions. You are making it seem like i'm someone who doesn't know how to work a camera. I bought the Nikon a year ago. People's choices change within a year.

Digital SLR Nikon D3100?

How good is the Nikon D3100 for an amuture photographer? It's the Nikon D3100 + 18-55mm Lens + 8GB SD Card + Tripod and Adobe Lightroom 4 for around £330.00
How good is the camera, or are there any others around the same price which are better?