The best places to buy a DSLR is your local camera store. The Department stores such as Sears, Walmart, Kmart, Best Buy and others usually have an inexperienced sales people with limited accessories and higher prices. Stores like Cameta Camera usually have low prices, a wider variety of cameras, accessories and a more experienced staff.
The best place to buy the Nikon d300 would have to be at Amazon's website. They offer very cheap shipping, as well as suggestions for things that you might need to go along with your new camera.
You can buy a Nikon D90 from the offical Nikon store or you can visit your local electronic store such as Dixons which should sell the camera along with any other cameras.
The best place to buy a Nikon 17 with a 35mm lens is online on websites, such as Amazon, Best Buy and eBay. Nikon 17 with a 35mm lens is an advanced digital camera.
Oh, heck yes.
I find the Nikon Coolpix good for film.
Nikon
You can buy a remote for the Nikon D60 but not the Nikon D40
On place where you can find reviews on the Nikon SLR is Cnet.com. Another place where you can find reviews is Best Buy's website. one more place I suggest looking for reviews are discussion boards and Walmart.com.
One may find a used Nikon digital camera on Kijiji, Craigslist or at Value Village. Models, quality and prices will vary due to the nature of the used goods marketplace.
The best places to find a good Nikon camera are Target, Best Buy or Sears. Target and Best Buy both come with support in case something happens to the camera. I believe Sears has that service as well. Also, these stores have knowledgeable salespeople.
A Nikon 80 400 is a camera that can be purchased from stores such as Best Buy or Radioshack. The camera can also be purchased from the official Nikon website, Amazon, or eBay.
The best place to buy a Nikon D80 kit would be a specialty photography store. Or one can check on a site like eBay which sells a variety of camera items.
I'm afraid this question is rather vague; you don't say where you are. However, Ebay will usually have a good range of Nikon equipment. In the UK, Ffordes, MXV and Mr Cad sell used equipment, Grays of Westminster only sell Nikon equipment and have a good reputation.
One may buy a replacement Nikon zoom lens at nearly any store that carries Nikon brand cameras. For example, one may buy a replacement Nikon zoom lens at stores such as Best Buy or Walmart. Alternatively, one may find them online at websites such as eBay or Amazon.