You can find a replacement lens cap for your Nikon L35AF camera at camera stores, online retailers like Amazon or eBay, or directly from Nikon's official website.
Amazon is a good place to start to find a refurbished Nikon camera online and they offer some very good prices for a refurbished Nikon camera online as well
Go to Amazon.com and type in Nikon D90 camera. Click on the model you are interested in and you will find customer reviews. You can read them over and decide if this is the camera for you.
The Nikon cameras from what I have heard is a good and expensive camera. If you want to find out more reviews regarding this camera then you would have to visit the Nikon website.
craigslist.
A good place to find a digital camera made by Nikon would be Staples. They have tons of choices and I bet they have digital cameras made by Nikon. So go take a quick look.
It really isn't cheaper to buy batteries online unless you are talking about a specific battery for your model of camera. In that case, I would call your manufacturer, but if you are just looking for standard batteries, any home depot or Wal-Mart will suffice.
You can find all your Nikon needs and all the accessories for your camera at http://www.nikonusa.com/Nikon-Products/Photography-Accessories/index.page. Amazon will have them at a cheaper price.
The best source to find out more about what Nikon offers is to go directly to the official Nikon site. Here is the website for Nikon: www.nikonusa.com/
Your Nikon Coolpix Digital Camera should have included an instruction manual packet. If you lost yours, the Nikon website will probably have some online instructions.
You can search for a Nikon D3300 how-to video on websites like YouTube or Vimeo. Just type "Nikon D3300 tutorial" in the search bar to find videos that can help you learn how to use your camera effectively.
Lenses for Nikon camera can be purchased from any local camera stores. However, one can find a better deal on some online stores like eBay and Amazon.